There's a real difference between having a villain being defeated, and having a weak villain. Just taking A New Hope as standalone, the villain is clearly Darth Vader, who is also obviously defeated. He doesn't exactly strike me as a weak or boring villain. The Green Goblin is the villain of the first Sam Raimi Spiderman, he's relatively interesting as such characters go, and also ends up very defeated. For a more recent example, the villains in Wonder Woman might have been cliche as all hell, but at least they were fun to watch and had motivations and did things.
Contrast with the walking plot device of boringness that was the villain Captain America: Civil War. Was the villain in Winter Soldier just the secret Nazi computer program, or was there another one? I can't recall. I can't remember a damn thing about the bad guy in Doctor Strange - I had to work to remember there was a human bad guy. I'm drawing similar blanks for the villains in the first two Iron Man movies (never watched the third, so no idea there).
Marvel movies don't have weak villains, at least from the ones I've watched. They have villain-shaped personality holes that they paper over with more smarmy hero one-liners.
(I will grant an exception for Spiderman: Homecoming though. It's almost like if you put the antagonist on screen and let them interact with people and do things they're more interesting!)