I’m failing to see where there’s some kind of downside here. What you describe doesn’t really sound like a bad experience.
We saw the same thing happen with mobile first on websites.
Or for that matter, that adding support for game controllers (something that has actually happened with Linux desktops) would led to curtailed development of non-controller parts.
Well, a lot of devs did move back to the terminal ;)
One of the most common actions among all computer users, zooming and centering a photo, is easier with a touch screen.
Even adding just that one thing is worth having a touch screen for.
Another example: working in the iOS simulator is now way easier because you can touch your apps that you're developing for iOS and iPadOS. And, by the way, macOS can run iOS/iPadOS apps directly from the App Store, so if there's something you really want to run that you just can't find a macOS equivalent for, there you go, you can just do it and interact with the app more naturally.
The value of “tablet mode” would mainly be if I want to do content consumption, like watch video or read a book, while on the couch or in bed since it allows a wider range of postures you can sit or lay in when you don’t have to rest it on a flat surface.
If you can’t fold it back I just don’t get the appeal.
The sweet spot for me is the iPad mini, but I tend to use tablets as glorified e-readers and video players; the only serious work I do on them is reading.
With that said, I have zero problem with touchscreens or convertable form factors. In fact, I used a Surface Pro for years as my main laptop, and it was one of the best Windows laptops I've used.
But again, I'm not a big fan of mobile devices as primary computing devices unless I'm actually working on the go.
Even for commuting back and forth between an office and a home office, I'd rather just put something along the lines of a Mac Studio in a bag — for a few months last year, it was actually a SFF (not micro, weighed about 10 kg) Dell OptiPlex in an aluminium briefcase, which was fine!