In Europe it's not uncommon (or at least, it isn't unheard of) to need to bring your own bed sheets and towels from home.
I’m not trying to brag but I’ve been to all seven continents of this world and many places in Europe. Never once have I seen this.
Presumably, bed sheets are so basic that they aren't even listed in the star criteria. Even in youth hostels, you may have to put the sheets on yourself or they might cost extra, but you don't need to bring your own.
Did you have some weird experience that you’re extrapolating wildly?
Its different for hostels tho