Totally agree on all points. One of my biggest regrets is that I did not start watching the Marvel films until after Endgame had left theaters. They were great on a widescreen TV, of course, by not seeing them in the theater I not only missed seeing these epics the way the filmmakers intended, I also lost out on the communal experience of being with other fans.
You are also right that going to the movies alone is an underrated pleasure. For years I would sneak away to the theater on Thanksgiving or Christmas afternoon for a respite from too much family chaos.
One other personal note. No amount of microwave popcorn will ever match the kind you get at the theater.