For routing, x86 is going to have the best perf for CPU intensive tasks like QoS. For wireless, mediatek is well supported upstream. WiFi is wifi 6 only though. Wifi 6E and 7 are in the works but will take a while to stabilize. My set up is an old lenovo thinkcentre nano IoT box as the router and netgear wax220 as AP, both running openwrt.
WiFi 6E works fine on OpenWrt, it's just that there are only two routers supported in ToH SmartRG SDG-8733 and SDG-8734. It works out of the box (I tried just as a test) on my MT7922 (RZ616) card in my PC.
