Not that I don't wish to have tooling available for me to modify, but I also understand this is thousand years of man work right there...
I don't doubt your thousand hour quote. But at the same time I'd say there is probably 10k years of garbage and cruft built in the current toolsets.
FPGAs need an LLVM moment. Right now, the current set of HDLs available are terribly unergonomic and pretty much re-implemented for each FPGA provider. We are roughly at the K&R C era for FPGAs. To get out of that, we need good middleware and open standards.
Once that happens, I think we can finally start making some real higher level hardware description languages. FPGA programing, in particular, seems like it would be fairly amenable to functional programming concepts.
The same could be said about highly efficient optimizing compilers and kernels. Nevertheless, we have GCC and Linux.
Synthesis, place and route are all much harder than simulation, so I don't think tools like vivado would suddenly be better if open sourced. Also I think vivado is great, but I seem to be in the minority on that one, but I guess it's my perspective as a HW designer dealing with HW tools all my life, vivado is a breath of fresh air.