I’m saying that your router and access point should be separate devices anyway, especially if you don’t want to replace said router.
My router doesn’t have wireless at all. I have a dedicated WiFi 6 access point for that, if I want to go up to a newer standard I just replace the AP.
Less about open source, more of just a practical stance. The thing about networking is that standards change all the time, and it’s better to have a single device serve a single role on the network than to cram all those functions into a combo box.
So an ideal network has a separate router, switch, and access point. Ideally two of each in redundant configurations but that’s not required for most people.