> I think one solution could be in licenses that force companies/business of certain sizes to pay maintenance fees. One idea from the top of my head.

This just doesn't work. Fully open source software (as opposed to source available) is so much more useful than the alternative that there's always going to be an OSS fork for any sufficiently useful project. AFAICT Elasticsearch and Redis have not really "won" by their respective license changes but rather have just fragmented their own market and sown the eventual seeds of their destruction.