There might be money to be made starting a startup that starts the revolution, but I don't know enough about the industry to figure out any business plan more detailed than that.
I've seen this claim many times before, but I never see any proposals about exactly how that would happen.
All open source FPGA tools that exist today are good enough for fun hobby projects (I use them every once in a while), but none of them have the additional features that are needed in the real world.
When pressed about it, people point to 50GB downloads, bad GUIs, and bugs in the tooling. Not that these aren't issues, but if that's all you can point to, then I don't see where the disruption will come from? In order to have that many bugs and 50GB of tools download, you need tons of code to begin with, and the functionality that it implements.
Right now, that's not there, and it very likely never will. It's such a niche domain.
Just build a modern design rule checking (DRC) engine with parasitic extractor. That's all you have to do. I eagerly await your release on github.
I agree with you that open source really is the only valid path forward. However, you have to convince some very smart people to join your cause and they expect to be paid up front.