Looking at this from another viewpoint, with all these new features that are bolted on to the OS every year mixed in with new APIs surely the whole OS has to be updated to support all of this, but it seems like parts that can be left that "barely" work are indeed left, a perfect example would be the music app on macOS.
This work from home approach isn't working and it's not only stunting the growth and polish of the OS, it's starting to really bring in a sense of disillusion among customers, that said...
Has software quality gone down, yes.
Is it the same across other manufacturers; yes.
This is completely unrelated but another industry let's say gaming, back when you bought Crash Bandicoot for the playstation that had an immense level of polish and stability, why? Because once it was shipped you couldn't push an update via the internet, once it was out, it was out, games these days day one patches galore.
So this new got to have it now, internet based delivery of software seems to be hurting all industries