Not disagreeing (or agreeing) with you about that, but as a coda I would note that I find it somewhat absurd that laptops have become the typical platform for developers. It implies something about what drives people's choices for working environment that I find strange. I do have a laptop, and I appreciate it being portable and thus being able to do work away from my (home) office. But most of the time I work on "desktop" system (Threadripper 2950X) with 3 screens, a fantastic keyboard, an even better mouse and many other things in the physical environment that improve my working experience. In short, it makes essentially no difference to me how "insane" MacBooks might be - they will never replace my "desktop" system for work.
Apparently, this is an area where if I'm not in the actual minority, I'm certainly in the quieter faction.
Many (most?) people don't have the luxury of two development machines. If I could have two, I'd probably get a laptop and a desktop too. But if I can only have one, then I'll take the laptop.
The option to work anywhere is nice, I have a dock that I just plug one cable into my macbook and the entire setup lights up and is ready to go. But sometimes i want to work from the living room, or work at a coffee shop etc. and all i have to do to enable that is just unplug that cable and put my laptop in my bag. It's some pretty nice freedom to be able to do that.
This doesn't mean that support would necessarily regress on existing platforms, just that there will be a window of opportunity to catch up to the state of the art.
As for the fixed function accelerator blocks, vendors who cooperate will have more robust driver implementations derived from their work to support customers who rely on it operationally.
This seems like obvious but really is not.
As long MacBooks keep being the insane machines they now are, they will soon become (and keep being) the best Linux machines available.
Just because people will make sure of that.