I would guess because "so good" does not equate with 100% and presumably the user's needs fall in that 5%.
replyLinux has been usable for non proprietary software for decades now. The fact that people are refusing to jump ship even when Windows actively undermines them and itself speaks volumes of people's aversion (or inability) to switch OSes.
Oddly I’m like mostly using proprietary Windows software on my Linux machine these days (games).
replyI also think the AI era goes very far in eliminating those 5% problems. I have a mostly non-technical friend who set up an old laptop with Linux for the first time and he told me that he’d never have been able to do it on his own without AI. Anytime there’s an issue, his solution is just a quick question or copy/paste away.