Worst part of Linux is the death by a thousand paper cuts. Bluetooth may work or not work. Apps may be compatible or not with Wayland. Power consumption may not be efficient. Computer may not resume from sleep. The browser may burn CPU when playing videos. Etc.etc.
Lots of stuff like this can happen, and I guess, anyone will experience one or two. I've been using Linux for a long time, and there is always something.
Everything can be fixed with patience (and experience, that one may not have), but Linux is definitely an O/S that needs some work, once one goes past a casual use. Casual users may not notice.
My favourite niggles: clipboard not being always shared, and file managers not sharing bookmarks data across them. These are definitely embarrassing.