We love to praise linux constantly and tell everyone to change to it (they should) but what are your biggest annoyances ?
Mine would be, installing software (made even more complex by flatpaks being added, among the 5 other ways there already were to install software) and probably wifi power management issues.
Unreproducible, random bugs that can be temporarily solved by repeating your actions a bunch of times until it works. Drives me nuts, and they show up all over the place.