I used to use an old Linksys WRT54GL v1.1 router for the purpose of testing homelab setups, but I have recently found that, as of 2022, it is unsupported by OpenWRT. So, I am now looking for a router to replace my old one. I don’t need anything fancy – I just need a router with WiFi connectivity (2.4GHz is fine, but 5GHz is, of course, appreciated, if possible), and a few LAN ports (gigabit would be nice, but it is not a necessity). By no means does it have to be a new model of router. So long as it supports a current version of OpenWRT, and satisfies my hardware requirements, it will be an acceptable recommendation
since your priority seems to be software support for openwrt and considering that you have ancient hardware doing the job just fine, you should go for an archer c7, it has 80211n wifi and 5ghz to boot and decent headroom for shenanigans.
you can get one brand new pretty cheap, even cheaper used.
great openwrt support too, cause its cheap and popular.