I've heard in a couple of places that the TV, streaming, and movie systems can't really make an appealing offer to top-tier YouTubers. YouTubers want the prestige of being a "real" content producer, and not "just" a YouTuber, but non-YT producers can't offer the level of control one has over their own channel. It's not even about money, it's about taking orders from some executive about not only content but monetization as well.
He said once his iconic red shirt and grey sweater started from a weeks long TV shoot he was doing where everyone wore a different color and he naturally ended up with several identical outfits for continuity throughout the shoot