yeah, corporate-backed projects basically always become corrupt sooner or later, we've seen this with Mozilla and others. On the other hand, the Linux ecosystem as a whole would be in a much worse state, because there would be much less capacity to make Linux daily drivable, most people would be forced into the Windows/Mac ecosystem to get the work done, which would be even worse
Actually, it isn't Flathub but Flatpak itself bending the knee via the xdg-desktop-portal thing, so it also affects Flatpaks from other sources (e.g. the ones builded manually with flatpak-builder) sadly. I wish there was another sandboxed format with that level of permission control. I like to have sandboxing and easily manageable permission system (which some call the "phone approach" and consider it a negative thing, I don't really get why, I didn't hear any clear, reasonable explanation from anyone) for programs which connect to the internet, for privacy reasons. I looked at Firejail earlier, but it didn't seem to have as finegrained permission system as Flatpak
But at least Flatpak can easily be removed from basically any system (except for maybe the immutable ones), while the init system can't really be changed on most systems