Oh boy, in 2015 Windows 10 was released, and it was extremely broken, including endless reboot loops, vanishing start menu and icons, system freezes, app crashes, file explorer crashes, broken hardware encryption and many broken drivers – so really it was about the same as now. Embracing LLMs and vibe-coding all around made this even worse of course
The main difference is that Windows 11 is already 4 years old.
Oh, Yes. Windows 10 had big issues on arrival. But this is also selective Amnesia. The Windows 8 UI was nearly unusable on release. Windows Vista was so legendarily broken on release, that even after it became stable, the majority of technical users refused to give up Windows XP went straight to Windows 7. And even Windows XP that everybody fondly remembers was quite a mess when it came out. Most home users migrated from the Windows 9x line of Windows, so they probably didn't notice the instability so much, but a lot of power users who were already on Windows 2000 held up until SP2 came out. And let's not even talk about Windows ME.
The only major Windows version release that wasn't just a point upgrade that was stable in the last century was Window 7 and even then some people would argue this was just a point upgrade for Windows Vista.
I'm sure that Microsoft greatly reducing their dedicated QA engineers in 2014 had at least some lasting impact on quality, but I don't think we can blame it on bad releases or bungled Patch Tuesdays without better evidence. Windows 10 is not a good proof for, consider Vista had 10 times as many issues with fully staffed QA teams in the building.