I see more and more complaints about bugs, anyway. I use it all day every day without issues, though. Not sure what to make of that. It’s not that I don’t believe those who are affected. I’m just not sure one can conclude that it’s getting more buggy with each release. Maybe the number of unusual use cases increases with popularity?
For me personally it’s not bugs as such. Bugs usually do get fixed fairly quickly (though something like this making it into a release candidate is concerning).
It’s half-baked features that don’t get revisited for years. We all know the new System Settings sucks; Sonoma hasn’t meaningfully improved it. The Notification Centre redesign introduced 3 (?) years ago is so much worse than the old design, but it hasn’t been touched since. Disk Utility is a shadow of its former self.
macOS is an established operating system, I would prefer them leave perfectly good features alone unless they can actually make them better.