I respectfully disagree. I think it is due to the constant mishandling of these various older IPs over the years by Hollywood. The younger generation has witnessed flop after flop, so they don't have any trust in Hollywood, just as many of us older folks have lost trust.
YouTube is a fascinating thing in that while we older dudes are able to continue to look at and enjoy our childhood IPs, the younger generation have also used YT to learn about those very same IPs and many have a great appreciation for those old IPs like He-Man, JLU, etc. and so, many are looking backwards to find quality entertainment to boot.
I don't think it's because the IP is old, it is because Hollywood proper is out of touch when it comes to presenting those IPs to a new generation, in contrast, the YouTubers who have been building an audience for a decade have also built good faith and trust, so that when they produce new IP, the audience will support their endeavors.
Plus, everyone loves seeing little David win against Goliath.
So this is really about building trust versus losing trust. Not really a generational thing at all.
You wanna know why Obsession and Backrooms is doing gangbusters while He-man and Spielberg are flopping?
Cause the zoomers didn't grow up with our media, they grew up on youtube. Our media is an echo of a past they only heard about and they have no interest in it.