There's also a big difference between "x works very bad for the untrained population, but let's pretend it doesn't, because my worldview demands some media conspiracy" and "x works well".
East Asian countries have almost everybody wearing masks. I really don't think using these things is as complicated as you're making it out to be.
Seriously, how much mask training do you think healthcare professionals get? Nothing that a 2 minute YouTube video wouldn’t cover, I’d guess.