Youre here aren’t you? Why do you think theyre called subcultures? Punk/punk idealogy was never mainstream until it was tamed, domesticated, and commercialized decades later
Pop ate punk.
It tried to. Luckily it didn’t like the taste and spit it back out. I think they called it Emo.

I’d say the Clash were simultaneously highly mainstream and true to the spirit of punk. Dead Kennedys as well, albeit slightly less mainstream.

Honestly I’d say there’s a lot of punk bands that enjoyed something close to mainstream success without being sellouts.

Rage Against the Machine aren’t quite punk, but they’re heavily punk-influenced. It’s amazing that they were such a huge commercial success.

As to whether they’re sellouts, that’s really complicated. They did generate a ton of profits for the machine they raged against. OTOH, I never would have heard their music if they hadn’t been signed to a major record label.