Come on, Stan Lee, Jack Kirby et al at Marvel were providing depth not really seen previously in most comic books already in the 60s, and still getting them past the comic code, and becoming really popular.
The depth was mainly in character development- a factor in whic DC comics of the era clearly lagged.
And while they did manage to get the occasional story past comics code enforcers, those were the exception rather than the rule...and the bulk of the edgier stories featured the same thing Brad Pitt & Quentin Tarentino's current entertainment epic does- Nazis.
Getting into the 1970s, you started to see Marvel & DC explore the post-Flower Power age with even edgier stories & heroes- Adam Warlock, The Punisher, Etrigan and so forth. But even so, potentially extremely edgy characters like Ghost Rider were saddled with fairly whitebread storytelling. Wolverine, for instance, despite running around with 6 18" adamantium claws at his disposal didn't manage to mortally wound anyone for about a decade. How many times did the Hulk level city blocks...and no mention of casualties.
Racism and sexism were addressed...but in a glossy and superficial way. Homosexuality was verboten. Everybody was straight. Almost everybody was white- except aliens- and male.
It isn't until the 1980s that you started to see both the boom in comic book popularity and consistently deep and meaningful storylines that had believable threats, challenges and consequences of the type that really inspire roleplayers.
And even
that pales in comparison to the 1990s and beyond.
(FWIW, my collection dates back to 1963, covering Marvel & DC plus several of the upstarts...)