> So if say Microsoft forks your library and its fork becomes more popular, they can't make it proprietary after capturing the market and effectively stop people from remixing what you made.
Neither can they stop people from such remixing if the project used a permissive license. The GP's project will still be there, still freely available for anyone to use however they see fit. Nobody is stopped from using it in any way.
The GPs project will become less relevant as the Microsoft fork becomes more popular, when it is fully irrelevant due to incompatible changes they can rugpull and everyone will have to pay them.
Neither can they stop people from such remixing if the project used a permissive license. The GP's project will still be there, still freely available for anyone to use however they see fit. Nobody is stopped from using it in any way.