Linux relies heavily on corporations using it.
Gecko is dead without Mozilla - if Mozilla bankrupts, no one has enough manpower to develop Gecko.
Even if code is GPL-licensed and in ongoing development, main contributor can easily force their design choices on downstream forks. If you redesign some system, downstream forks have to reimplement their changes on top of refactored code. And they don't have enough manpower for that.
Well, governance of open source is probably not solvable, like most of human relations.