I have just been thinking. I didn't watch any of the MCU until a little before Infinity War came out. I think I saw Hulk years ago and sort of watched Ironman ages after it came out but that is it. I didn't realise the movies were all tied in or connected at some point. Never bother with Agents or Shield or any other show either. In fairness I just thought they were just standalone superhero movies. Characters I knew nothing about. I think it was when Black Panther came out (I had zero interest in that film upon release) that I sort of clicked or read something about the whole MCU. My missus didn't know about the MCU either. I think it was then that I hunted down the films that belonged in the MCU and started to watch them. I googled what order to watch them. I think I appreciated the earlier movies more knowing what it was all about.
I am pretty sure there were more people like me, knowing nothing about this whole thing and then got hooked once they started to realise and binge the lot to catch up.
Even when Guardians of the Galaxy came out I started to watch it but though it was a stand alone movie and I just thought it was a crap film.. watched it when I binged and I realised what I missed, it was a great film.
The MCU is pretty much a winner in my eyes. the bar is high and if they pull anything off that matches it or beats it I will be amazed.... But saying that, they haven't made a flop yet, all the films are top for me.