If you want to operate an airbnb in Berlin you need a hotel license (unless you actually live in the thing at the same time, or only do it for I think about a month a year, say when you’re on vacation). Long story short the city isn’t giving out any licenses in areas with high rent pressure, which is basically all of Berlin.
But those things are highly regional, there’s plenty of villages in the alps with an absurd amount of tourist accommodation compared to the number of regular inhabitants, but they also don’t have any industry but family farms and tourism. If you own something on Sylt and somewhere else you’re paying sky-high secondary residence taxes (rich fucks don’t rent they just buy holiday homes).