That said, I've been using Asahi for a month, and I'm ditching it. Maybe in a year or two it'll be stable, but for now it's got too many bugs and unsupported features. A lot of the problems come down to Wayland and KDE/Gnome, as you literally have to use Wayland. But there's plenty of other buggy or challenging parts that all add up to a very difficult working experience.
One of the biggest challenges I see is support for hardware and 3rd party apps. Not only do all the apps need to support this slightly odd Arm system, but so do hardware driver developers. I never realized before just how much of a Linux system works because most people had an incredibly common platform (x86_64). Even if Linux on Mac became incredibly popular, it would actually take away development focus on x86_64, and we'd see less getting done.
(This kind of problem is totally common among Linux laptops, btw; there's a ton of hardware out there and Linux bugs may exist in each one. Adding a new model doesn't add to the number of developers supporting them all. If anything, the Mac is probably benefited by the fact that it has so few models compared to the x86_64 world. But it's still only got so many devs, and 3rd party devs aren't all going to join the party overnight)