Barring some exponential increase in the usability of FPGA tools, I think the mainstreaming of these technologies will forever remain just around the corner.

More coarse-grained architectures like GPUs or reduced-scope architectures with a less intense cognitive load like the programmable IOs found in Raspberry Pi Picos or some Texas Instruments MCUs seem like a much more feasible solution for the vast majority of potential FPGA use-cases a tinkerer would run into.