vimtutor is free because vim is free

There are tons of books and other resources for learning vim that are not free. I'm not sure why you would find that surprising.

I own said books. Used NeoVim for years.

Said books are genuinely useful, mostly.

Drew Neil's explanation and POV on how to approach Vim, gradually assembling all Vim commands into repeatable period commands. Followed by bundling those commands into recordings with q.

Highly endorse Drew Neil. Is incredibly useful.

This website offers little more than vimtutor with fancy graphics.

Charge for offering a service. How dare that guy.

Isn't this a forum founded by a venture capitalist/startup guy? I don't understand why you have an issue with someone charging money for something they made.

a venture capitalist would ask this exact question

A fair point, but it seems like their issue is with monetization at all, and not with it being a poor business model.