That's really interesting to me, and I'd totally be on board with that. Because it makes it about the story, and not about which CGI monster can punch the other CGI monster harder.
I think the Marvel movies have generally been pretty okay about this. Even when they do raise the stakes a little, they can do it in a way that doesn't have to feel repetitive. Technically, the entire world was at stake in Doctor Strange, but it felt like a more personal story, and the movie doesn't dwell on scenes of mass destruction. The way Strange defeated the villain was clever and enjoyable.
On the other hand, you look at something like Thor: The Dark World (admittedly the Marvel movie that gets the most crap from people), and the entire world is threatened with destruction by a villain who wants to end all existence and is perfectly content to no longer exist. Not only does that make for a dull villain (no reasoning with someone like that), but the stakes got so huge that it became unbelievable that no one called the Avengers in.
And yet, no one does. Certainly the stakes Thor was against in Dark World were higher than the stakes that brought the Avengers together at the beginning of Age Of Ultron - in that movie, they get together because there's an evil stick that can't be left in the wrong hands. (Oversimplification, I know.) If an evil stick was worth bringing the whole team together, surely the actual destruction of the planet as threatened in The Dark World would pass that threshold. Getting back to the example of Ant-Man, another reason to love that movie: Paul Rudd knows he's in over his head, so he suggests calling the Avengers. Michael Douglas is able to use a funny one-liner to dismiss that suggestion, so the movie can address the existence of the Avengers without needing to use them.
Josh - You're obviously a smart guy but I'm concerned you may be watching these movies sober. Just kidding but I was never into the original comics so I just love the cinematic and technical excellence I see in pretty much all Marvel titles, especially compared to the DC releases. Can't wait for this latest installment.