I think looking at the affiliate systems of those two providers and my guess at the volume of demand for self hosting a scrimba alternative its unlikely to make a substantial amount of money. In my readings open source business models are usually around either providing enterprise support or enterprise closed source infrastructure/extensions to the open source package. I can imagine affiliate links working well if the volume of users is high, such as a popular library such as next.js - but that requires lots of developers to have a use case for the library/service