Putting aside that Zoom is not Facebook, "Zoom's choice to not allow gallery view" sounds very much like, "How long have you been beating your wife?" Zoom has not implemented gallery view. We know nothing about the whys, hows, and whats of the matter.
Look, I prefer webapps when possible and keep mobile apps to a very minimum on my mobile (and preferably from F-Droid, at that). But I also understand that you can only do so much in a release and if your engineering team expertise, backlog, users, sales, EVERYTHING, is centered around native apps. Then damn it, you're going to make your native app look stellar because otherwise your competitors will get a leg up over you.