Re: app issues, I've had HBO Max crash on me about 100x over the last year'ish - no exaggeration. This was across LG C1, Roku, PS4, Xbox Series X, and Android. It's improved substantially over the last couple of months, but it's still the most likely app to have problems. I would have cancelled a long time ago, but the content kept me hanging on. It looks like I'll be cancelling with the Discovery acquisition.
IME, Netflix still stands heads and shoulders above the rest in terms of UI quality, functionality, reliability, and speed. I've often thought that they should license out their stack. My ranking for apps (which I've used for at least six months), would be Netflix, Hulu, Apple TV, Disney+, Amazon Prime, and HBO Max, with Prime and Max often infuriatingly bad.