Can someone explain to me why they might have gone with this strange pricing model instead of the very simple revenue sharing model that Epic uses?

“Based” is typically used to describe someone who says/does something without caring if they’ll be judged for it. Most commonly, it’s shorthand for “That’s a controversial opinion and you are bold for saying it, but I agree with you.” It turns the previous sentence into an adjective, which is a little weird but it makes sense eventually.

So if I had to choose a single word as a synonym, I would say “Bold”.