While obviously very difficult, making Windows into a much more cohesive and bug free experience isn't impossible. Windows used to be a lot more cohesive, and I have no doubt it's possible to go back to that while also keeping the stuff that's good. The problem with that is that it requires walking back a lot of decisions which were made by people higher up the chain than those actually making the changes, and it's hard to walk back bad decisions by people high up the chain.

Microsoft also at least used to be capable of fixing bugs in Windows pretty well. XP Service Pack 2 consisted of mostly just that, in order to make a much more stable OS. And it worked quite well. But that was back in the day when Microsoft had a proper QA department and actually gave a shit about the user experience.