Why an Open Source GPU and PCI-E Controller

Sometime ago, I set out to create an open source GPU(currently using Clash-Haskell -> Verilog -> FPGA) that supports Linux Mesa as well as an accompanying PCI-e controller.

Needless to say, this is quite a challenging task to do in one's spare time after work. I'm wondering if there is value in such an implementation beyond doing it for the sake of doing it.