Kind of. There is certainly a market for aspirational tinkerers. There are people who would (and do) buy routers to install stock DD-WRT and run them basically unchanged. But that market is small and already saturated. I can type “best routers to use with DD-WRT” into Google and get a list of options that cover all price points already. Most of the options aren’t even competing directly for that narrow market but they support custom flashing so they saturate the market incidentally.

Comparing to Raspberry Pi, the analogous question would be “is there a market for Raspberry Pi with Pi OS already flashed onto a memory card”? And the answer is not much. Someone preflashing a stock image doesn’t provide much if any value.

Someone starting a new router company better have more of a value proposition than just “I’ll preinstall DD-WRT for you”.