Sure, I think it's perfectly reasonable for OpenSea to charge 2.5%. I think everyone will charge what the market will bear.

It's interesting to ask why YouTube's take rate is 20x higher. I think one big factor is that when you facilitate a high-value transaction like a house or a blue-chip NFT, the absolute amount of the commission gets too huge if it's more than a few %, and users will find ways to complete the transaction without paying that.

Also it's about the degree of how much the platform sources customers/users for you. If OpenSea sellers would be helpless to find a buyer for their NFTs without OpenSea's audience, then I'd expect OpenSea's take rate to go up a lot. But the main place people hype their NFTs to stir up demand isn't OpenSea itself.

On the other hand, YouTube itself is how most YouTubers find people to watch their videos and make money. So that's a big difference in leverage. If they leave YouTube, their audience size will probably drop by 50%, unless they've built their own audience, in which case they should consider using solutions like Vimeo that will only cost 1-10% commission.

As a meta-point, I never see the Chris Dixons of the world doing this kind of super basic analysis of where take rates come from. It's incredible to me how shallow their reasoning is, as demonstrated in the screenshotted slides.