avengers to me was best with the b cast of people like vision , black knight , Clint as Goliath ,wonder man, Hercules those type of characters . Avengers was launched as a way to draw interest and combat the justice leagues popularity
Your culturally out of synch you do realize that
if your hating on superman and sayin the xmen as a whole are bigger than him . He had a animated show during the 90s, Lois and Clark , death of superman , his marriage to Lois lane was all over the news too. And superman Returns ( a poor movie good superman and effects but story sucked ) made money in 2006.
Christoper Nolan and the dark knight trilogy did help though it made Nolan a household name that represented quality and so when people see that he has a hand in superman they figured they'd get a serious gritty darker take on supes.which is so popular nowadays .
You bringing up comic book sales and Rare collectible prices mean nothing . Magneto is not as famous as supes ,neither is storm or wolverine . Their characters might sell more books now but green lantern was too is he more popular than superman