I’m not stepping inside a theater any time this year (at least - I’ll be refraining long after others return), but as to the rest, clearly you aren’t frequenting the right theaters. My preferred theater has 8-10 minutes of previews (about that much, I actually like), and zero commercials, its auditoriums are quite clean, and the staff will come deal with people who won’t shut up or turn off their phones. One or two of the staff come in at the beginning, introduce themselves, go over the rules, and tell how many minutes of trailers there will be. It’s really quite civilized. And I miss going there.
As far as shooters at movie theaters go, yes, that has happened once or twice. But it’s not like theaters are a hotbed of shootings. If not getting shot is your overriding concern at all times, there’s a whole list of other places to avoid first.
(And in general, it’s insane and depressing that mass shootings are a thing that’s common enough that one sometimes has to check which mass shooting someone is speaking about - that’s one of the things that makes the US “special”. Sigh.)
