That's precisely how something ends up becoming ubiquitous. You, and everyone else, start having fun on it and then suddenly it's a locked-in platform monetized by them.

YouTube started exactly how you described it, some silly thing not meant to be serious and today powers multiple 100M+ businesses using it for content to reach mass audiences.

> I don't think serious things are meant to be built on this.

I read at some point that projects at Google didn't get a greenlight unless there was a reasonable expectation they could be used directly or indirectly by a billion people.