Seeing as how Marvel sometimes scales the age of their heroes to line up with world events, this is pretty good heads canon if you ask me. Better a dimension shattering crisis than having to make a deal with the devil.My favorite head canon for why no one ages in Marvel is the Franklin Richards doesn't want them to.
As for DC, there's a crisis that resets time like every two weeks.
Ah. Yeah. That would make sense then. Have you read much of it? What's your opinion on it? Most of my DC knowledge comes from the '90s Timmverse and then what I pick up here and there through conversations. I know DC has actually put out some good stories throughout the decades, but I just don't find a lot of their heroes compelling. I was always more into Marvel out of the big two but didn't even read them that much because I hate major events and crossovers which they seem to do every few months. So when Valiant resurfaced, I jumped in feet first since day one and haven't regretted it. They're doing a great job in my opinion.
I don't read any comics anymore but I like to keep up on what's going on. They folded the Watchmen into DC proper so that's pretty shitty but the overall reaction is positive. I recommend NerdSync on YouTube. I watch a few other channels but they're the best. It's hard to explain on my phone what they do but it's not recaps