I think it is much healthier for a franchise to put out solid entertainment every time out where you are practically guaranteed to see something at least decent, than a total crapshoot where you might get a classic like Logan, The Dark Knight, and Into The Spider-Verse one time and total unwatchable crap like Fant4stic, Batman v Superman, and The Amazing Spider-Man another. I think the box office bears that out. It is more important to avoid the landmines that can kill a franchise overnight.
That said, I do think people are harsh on Marvel in that regard. They DO have some really fantastic movies. Winter Soldier, Civil War, Guardians of the Galaxy, Iron Man, Black Panther, Infinity War, Ragnarok are all among the very best CBMs, IMO. Saying that other studios either hit a homerun or strikeout while Marvel is content with a single, isn't really accurate. Marvel has homeruns. They just don't strike out. They may not hit a homerun every time, but nobody else does either.