Apple’s newly redesigned iMac measures just 0.45 inches thick. That’s a hair thinner than the original iPhone. It’s thin enough to wedge under a wobbly table.

But to make a desktop computer that incredibly slender, something had to go. Unfortunately, left on the chopping block were some capabilities you might actually want in a $1,300 desktop computer.

Gone are the large-sized USB ports many of us still use to plug in gear. Gone, too, is the ability to later upgrade your memory. This iMac is no longer even an all-in-one computer: Apple had to move the power supply to an external brick-like on a laptop.

An obsession with thin design has taken over consumer tech, and Apple is its leader. For you, that affects a lot more than just style. Going thin shapes what a device costs, what it’s useful for, how long it will last and what kind of impact it might leave on the environment.

Even if you’re not in the market for a new iMac, this computer is a case study in the strange priorities that shape so much of the technology we use.

This 24-inch computer, the first iMac powered by Apple’s own M1 processors, does contain lots of useful upgrades over the 2017 version. It’s faster and has a much-improved camera and a Touch ID fingerprint reader on the keyboard. It also comes in a rainbow of colors that will give anyone old enough nostalgia for the original all-in-one iMac.

I had been eagerly awaiting this iMac to replace my 5-year-old model. I’ve long been one of the iMac’s biggest fans: A desktop computer might sound old-school, but a big, beautiful screen is pretty much the ideal portal for getting work done.

But the new iMac I’ve been testing for a few weeks is a departure from my old one. It’s essentially an iPad on a stand. Actually, it’s less useful than that, because the iMac doesn’t have a touch screen.

Apple isn’t the only tech maker chasing thinness. Acer made an even skinnier desktop computer called the Aspire S24. But Apple sets the priorities for the industry and our expectations for what “progress” looks like in tech.

There are good arguments for thin handheld devices: Skinny phones fit better in skinny jeans. But even with Apple’s mobile tech, we’ve been burned. The ultrathin “butterfly”-style keyboard Apple introduced for laptops in 2015 created so many problems that Apple eventually abandoned it. Some people still haven’t forgiven Apple for removing the headphone jack in the iPhone 7 to add battery and waterproofing without making the phone fatter.

The arguments for a thin desktop computer are more of a stretch. There may be people who only care that this iMac is cuter. Apple believes it’s redefining the desktop computer into a device that can be at home in a kitchen or living room, or even picked up. (I wonder, though: Isn’t that what an iPad is for?)

We’re talking computers, not stilettos, so let me be unabashedly practical: To really evaluate the new iMac, you need to look inside.

What we lost

To help me understand the ramifications of an extra-slender iMac, I called up iFixit, a repair website that’s well-known for doing gadget teardowns. IFixit let me watch while it sliced into the new iMac to see what compromises had to be made — and learn what happens when an iMac inevitably breaks or is too slow for the latest software.

The root of all the change for the iMac is that Apple gave it a new kind of brain. Instead of the Intel processors Macs have used for years, Apple is now using its in-house M1 chip, similar to the ones found in iPhones. The M1 chip gets less hot — meaning the iMac doesn’t need large fans inside.

I asked iFixit to show me what Apple did with space it got back from the fans. On the plus side, it added super-wide sound chambers to the speakers, so music sounds great. It replaced the webcam at the top with a full-high definition model.

On the minus side, the thinner imperative took over. Now that it could fit the brain of an iMac into a half-inch body, Apple cut other parts that just didn’t fit. First went the power supply, the part that transforms the electricity coming out of the wall. Now the iMac has an external power brick. Maybe you’ll just throw yours on the floor, or maybe it’s one more thing for your cat to chew on.

Next, Apple cut the ports on the back of the computer. The new iMac only works with smaller-sized USB-C plugs, which can do lots of things but don’t fit many of the cables and devices we already own in a larger shape known as USB-A.

“I don’t see any way USB-A would fit within half an inch,” said iFixit CEO Kyle Wiens.

Apple also cut the flash-card reader included in past iMacs, making one more thing photographers need to buy. Even the basic Ethernet port, used in many schools and offices to hardwire Internet connections, was too big. Instead, Apple stuck Ethernet into the power brick, and charges $30 extra for it.

What this means is that anybody who plugs things into a computer either has to abandon old devices — for me, including backup drives, a DVD player and a lifetime’s worth of thumb drives — or buy a bunch of unsightly adapters known as dongles. By the time I plugged in mine, the back of the sleek iMac looked like a rat’s nest.

I’m sure these weren’t easy decisions for Apple. Perhaps doing things my way would have made the computer more expensive. But these were all possible on the previous iMac.

And everything but the SD card reader is available on the latest Mac Mini, Apple’s other M1-powered desktop computer that doesn’t happen to be as thin as a pancake. That $700 computer, which doesn’t come with a monitor, is the best choice right now for anyone who might need a desktop Mac for creative tasks.

Sacrificing longevity

Even if you couldn’t give a rat’s nest about plugging into ports, Apple’s thin imperative chips away at something else you might want: longevity.

My old 27-inch iMac has a little door on the back to upgrade memory after the fact, a real help for future proofing. IFixit showed me why the new iMac wouldn’t need a door: Its memory is permanently soldered in place.

Apple says this design makes its memory faster with the M1. But it also means if you someday develop a new passion for, say, computer animation, you’d have to buy a whole new computer to get more memory.

Also fixed in place: the iMac’s hard drive. Aside from limiting upgrades, that poses challenges for data recovery and even security. (Earlier this month, Apple paid a multimillion-dollar settlement to a woman whose risque photos and videos were shared by technicians repairing her iPhone.)

And what about when your iMac inevitably just can’t keep up in six years? As recently as 2014, iMacs could transform into a monitor for another computer. But Apple no longer supports what it calls “target display mode.”

What about if your iMac breaks? IFixit found that while the fans, speakers and webcam are all reasonably modular, they’re tedious to access. To open up the iMac, the iFixit team used what looks like a pizza cutter to slice through glue that holds it together.

The glue isn’t new on this version of the iMac, but it “would be so much easier if they just had a couple of screws,” said iFixit senior editor Sam Goldheart.

Overall, iFixit gavethe new iMac a repairability score of 2 out of 10 — one notch lower than the previous model. Apple, of course, offers its own repair service. But you at least deserve the right to repair your own tech.

These choices have an impact on the Earth, too. Apple touts the new iMac as being “better for the environment” because it uses some recycled materials. But the biggest environmental impact Apple could have is designing its hardware to be repaired and reused, rather than thrown away.

The new iMac “is less and less a computer, and more of an appliance,” said Wiens. “Computers are complex, and you need hardware flexibility to deal with problems that come up. Apple has systematically removed all of those options.”

This is partly a philosophical divide between Apple and people like Wiens. Turning computers into appliances can simplify them: You don’t need to know about what’s going on if it just works.

But Apple’s appliance mind-set is also self-serving, because it means we have to keep buying new stuff. You may already have a box of old iPads and iPhones you aren’t using after upgrading. Now you can add an iMac to the pile.