> If people find it useful but enterprise adoption is lagging, doesn't that indicate there's still a big upside?

It could indicate that many people find it more of an entertainment product than a tool, and those are often harder to monetize. You've got ads, and that's about it, and puts a probable cap on your monthly revenue per user that's less than most of the subscription prices these companies are trying to get (especially in non-USA countries).

(I find it way more of a tool and basically don't use it outside of work... but I see a LOT of AI pics and videos in discord and forums and such.)