Forgive me if I am coming from a naive position, but in the case of PHP specifically, I don't think funding is the problem. PHP is fucking obsolete. The paradigm is obsolete, and the implementation is obsolete. The recent php2shell exploit is a case in point. The solution required a 13,000 line patch. This is not an issue of a simple mistake being overlooked due to constrained development resources. This is what it looks like when the Jenga tower of technical debt finally begins to collapse. This event should be looked at like the OceanGate implosion of software engineering. 
I mean no disrespect to the core maintainers, but IMO anybody developing software based on PHP today is practically negligent. The project should be wound down into stasis, like X11. No application developer without at least a roadmap to adopting some more modern development practices should be taken seriously.