So, I was curious if you are correct and the market has changed a lot, or if I'm correct and most peripherals still use USB-A. So I checked out the website of a tech reseller, sorted their keyboards by most sold, and counted the technology used.
Before I stopped counting, I found 8 wireless keyboards using bluetooth, 9 wireless keyboards using a USB-A receiver, and 10 wired keyboards using a USB-A cable. It seems like USB-A is still alive and well in the peripheral ecosystem.
It's a website which is commonly used by gamers, so wired keyboards may be over-represented compared to the general population. But it clearly shows that actually, USB-A is still really commonly used in new peripherals sold today.
In the context of discussing the port selection of an iMac let's not forget that the device already comes with wireless keyboard and mouse/trackpad. While using your own input devices is an option very few customers will want to make use of it.
Yeah, it should go without saying that gamers and people who code are in a different class: hobbyists. I'm one of them, and most of the people on this site are too. We love our periphs. I have a wireless (mech) keyboard and a wireless mouse that both charge via usb-C cables, though it is something I filtered by when I was shopping for them a year or so ago in anticipation of this happening.
I think Apple (correctly) determined that these folks will tolerate whatever they put out, buy adapters to use their beloved special keyboard, etc. And for the ones who won't tolerate it: they're probably not buying Apple hardware anyway.
I mean, now your argument has changed from "most peripherals use bluetooth so it doesn't matter" to "most peripherals use USB-A, but many Apple users will nonetheless tolerate the lack of USB-A on their desktops". I can't really argue against that, and maybe it's correct.
EDIT: Just to respond to the "gamers and people who code are in a different class" thing: I went to a different store which is more general, went through the most sold keyboards, and skipped all "gaming" keyboards (so everything from Razer, everything branded Logitech G, everything with RGB), and counted to 14 bluetooth keyboards and 19 keyboards which require USB-A (7 wired, 12 with the USB receiver dongle). People just use USB-A peripherals a whole lot. (Store URL: https://www.elkjop.no/INTERSHOP/web/WFS/store-elkjop-Site/no...)
I think we mostly agree, we're just splitting hairs over the word "use". I'd say my mouse "uses" bluetooth instead of USB, even though it does still technically "use" USB as well to charge, albeit very infrequently.
I am surprised that most peripherals do still use USB-A to charge, and my argument did change to reflect that new information.
I'm not talking about devices which use USB-A to charge, I counted all peripherals which have the capability to connect via Bluetooth in any form in the "Bluetooth" category. If I counted every peripheral which comes with a USB-A charging cable as a peripheral which requires USB-A, the numbers would look even more bleak.
The only keyboards I counted as requiring USB-A are ones which are wired with a USB-A cable, and ones which are wireless but only have the ability to use an RF receiver dongle such as the logitech unifying receiver. Your mouse would be counted in the "Bluetooth" category.
I have a recent vintage Logitech mouse (came out this year). The charging port on the mouse, is USB-C, but the charging cable it came with was still A to C. Same goes for the 2.4Ghz unified dongle it came with.
Before I stopped counting, I found 8 wireless keyboards using bluetooth, 9 wireless keyboards using a USB-A receiver, and 10 wired keyboards using a USB-A cable. It seems like USB-A is still alive and well in the peripheral ecosystem.
Here's a link to the search results page I used: https://www.komplett.no/category/10264/datautstyr/pc-tilbeho...
It's a website which is commonly used by gamers, so wired keyboards may be over-represented compared to the general population. But it clearly shows that actually, USB-A is still really commonly used in new peripherals sold today.