If there were a single corporate controlled entry point all these people were funneling into there would be posential for enshittification. Even if a single free vertically integrated project like debian suddenly had the majority of all PC users it would probably be impossible for them to avoid the corruption of money. But the linux ecosystem appears to currently be growing in a manner that preserves its diversity and organic nature and thus seems able to remain quite healthy in doing so

Embrace, extend, extinguish.

I would be incredibly weary if someone like Meta, Google, or Microsoft started their own distro. Make a solid distro with lots of bells and whistles few distros have, pre-install it on the hottest gear, poach the best devs away from open-source projects, exert more and more influence over kernel development, wait for a majority to get locked in and then start making parts of the OS proprietary so open-source can't keep up, and the dominoes fall from there.

Obviously not blatant money/data harvesting like with big tech companies, but corporate strong-arming has been done on Linux (systemD) and can be done again. Granted it's much harder on Linux (in the case of my SystemD example there are distros like Void or Artix) but there is still a risk imo.