My main issue with the MCU as a whole is that the first phases were clearly building up to the big baddie at the end, they were on a defined path that lead to that showdown. Now, I have no idea where they are going. It's like the difference between a rifle and a shotgun.
And while I know more than a few movies weren't good in some respects, but I loved them because they were part of a larger, epic story and there was some sense of direction.
And fwiw, I actually did like a lot of the older stuff, even as standalone movies. I'm not really a movie connoisseur, so I don't need movies to be great for me to enjoy them. I enjoyed the Thor movies, Iron Man, really most everything pre-Endgame. I didn't hate any of them. There definitely are tiers of movies within that group.
The main issue I have post EG is that lack of true sense of direction and the feeling like well, we're just sitting here waiting for some big reveal that hasn't really come yet. I still like some of the shows and movies, but just don't feel as connected to the big picture.
That said, I am looking forward to Secret Invasion. I hope it ups the ante a bit.