They are the ones wearing the masks out in public.
I will speak for Austria, however, what I say is true throughout Europe. Throughout the pandemic, Austria has had strict masking rules with nearly 100% compliance. My neighbors and I wore masks everywhere for two years. I rarely (ever?) saw people not wearing masks when they should.
Austria also has provided free PCR tests the entire time as well as access to vaccinations.
Recently, due to various reasons, the masking rules have significantly relaxed. FFP2 masks are currently required on public transportation and in essential shops, like grocery stores. Austrians continue to comply at nearly a 100% rate with those rules. I’m on a public bus right now and everyone is masked, for example.
That said, if Austrians aren’t required to wear a mask, they won’t. You won’t see masks in the street. You won’t see masks in museums or at performances. So please stop being surprised or upset by the fact that Austrians/Europeans are only masking when required.
But I get it. American tourists need to test negative to return to the US. So you will wear your masks everywhere. Just don’t look down on locals for not having your issues or risks.