Same. Been running OpenWrt for years now. I select hardware that runs OpenWrt and never (well, only once, truely) have had to reboot a device due crashing. That old "reboot your router" is just not a thing (touch wood).

I'm sure it helps that all my infrastructure is on a UPS. I've found that even Raspberry Pis can be long-term reliable servers, running ubuntu server and on the UPS.

Another thing that seems to help. I separate function. One box functions only as the router. The wifi boxes only provide wifi endpoints - they do not do routing. And so on.