The MCU wouldn't be what it is today without theaters. The Rock as a movie star wouldn't be what he is without movie theaters. And no, i'm not saying that because of money, i'm saying that because the movies are obvious big draws that are highly anticipated and best experienced with a group of friends. It would be much harder to determine if something was the same level of success on PVOD because PVOD releases generally have one weekend of hype and then no one talks about them again. Like, would Iron Man even have gotten a sequel if it was released on PVOD? Obviously we'll never know and the past is the past, but Iron Man was a much less mainstream character back then and I honestly don't know if it would've done well enough to garner the financial support for the entire MCU we have today.
Speaking more in general and less about the MCU - so much crap gets thrown on streaming that it's tough for people to know what's worth their time anymore. For every Mandalorian, Irishman or The Boys, we get about 40 crappy series in between and a bunch of B and C tier movies. Even if a high caliber movie were to drop on Netflix, it may not get a sequel due to the sheer amount of crap that gets dropped on there. The tease us with stuff that "looks" good from a trailer (like 6 Underground, for example) and then the final product is cheeks.
I'm not going to argue that movie theaters aren't dying quickly right now. But almost every major film for this year has been pushed back to 2021 for theatrical release. Until someone can prove that big budget blockbusters can be just as successful on PVOD as they are in theaters, then not much will change besides a shorter window. People tend to have a negative reaction when movie gets movied from theatrical release to streaming/PVOD, almost as if it's a "demotion".