And shortly after Wirth launched his RISC-5 system, the original FPGA board went out of production.

Which most likely wasn't predictable for him.

FPGAs were never that maker friendly, due to the whole ecosystem.

It probably was NRND on mouser/digikey by then... not that there was much choice in 2013- you went with what you had instead of $1000+ dev boards.