Got through all the Marvel films...
I don't think it's fair to compare the avenger films to the individual films as Avengers just felt like a combination of greatness that you could pick faults in but says more about you as a person for looking to criticise such work.
Thor Ragnarok was my favourite non-Avenger film. It was like the producers let their hair down and thought "let's have some fun". Seemed pretty pointless when it looked like Thanos had destroyed everyone from Aasgard one minute in to Avengers Infinity War, but thankfully the legend that is Korg made it to Endgame with his Hawaiian shirt playing fortnite. That said I didn't find Loki convincing as a bad character so when he transitioned over time in to more of a comedic fool I was relieved.
Captain America is easily the best Avenger to get behind though. Thor is too much in and out of those films, and Tony Stark is an irritant even though the Iron Man films in isolation were really good. Hulks fine albeit I think I preferred the version of him in Thor Ragnarok the most. Nick Fury can do one.
Wasn't as keen on the Guardians of The Galaxy films as the other films. Chris Pratt and Dave Batistas characters just felt lame in comparison to the others. Wasn't sure how I'd feel about Doctor Strange, Ant Man or Black Panther but got in to those films and behind those characters pretty quickly. I didn't mind Spider Man by the end, which I thought was never going to happen as to me Spider Man is Tobey Maguire.
I was hoping Vision would play a bigger role. Don't really think you could warm to his character until the Wanda Vision series kicks off. Wanda is still 100% the Avenger you would not want to piss off though.
As a collective I'd give the Marvel series a 9/10.