A RPi is not equivalent to what most would use as a COTS router, which includes a GbE switch and some kind of modem (DSL or cable). The latter on its own needs a few Watts.
On the contrary, OpenWRT and a good CM4-based board allows the Pi to run pretty well as a gigabit router :)
That’s not much of a router with just two ports and no WiFi.
No CM4 and accompanying carrier board needed . A regular RPi4 with a USB3 gigabit adapter makes for a good gigabit home router. I have been using one as my home gigabit router for the last 14 months without any issues.