Personally I haven’t. While Linux is imperfect, choosing the right distro makes the rest of the experience straightforward. And with it’s whole complexity, I find Linux more user friendly than Windows. Even driver issues, broken shadow file ownership and KDE specifics only made me more confident about my choice to use Linux after I solved everything.
Yeah, device support is the biggest issue. But the OS as a whole is pretty good. I used it with a OnePlus 6T and a Nothing Phone 1, both of which have pretty decent support. Some things about it were broken, and I didn’t try putting in a SIM card and making calls or texts, but the overall experience was good. I have high hopes for when we eventually get good “flagship” linux mobile phones that have full PostmarketOS compatibility.