Agreed. Stubby and Unbound was the defacto solution for encrypted DNS and was used as plugins for OpenWRT as well. DNSPrivacy's push to extend those bolt on solutions certainly extended the rise of encrypted DNS and enhanced privacy for all.
What I was pointing out was that AGH includes their own encrypted DNS internally. They do DoH, DoT and DoQ. If you have a big network or want to run your own resolver internally Unbound would be preferable. However you can simplify your network by just letting AGH do which ever encrypted DNS service you wish internally and avoid extra troubleshooting with external services?
(edit) Its also preferable that way for people with older smaller routers instead of minipcs. There is limited memory and space on those routers and additional programs and space all add up to a slower experience. Ideally if AGH can sort their DHCP stack out properly then AGH would be a full stack replacement for dnsmasq, odhcp and dhcp from OpenWRT. You would simply disable those OpenWRT services. Setup AGH and gain encrypted dns and full dhcp with filtering and parental controls. (it would also simplify the setup we currently have to "adjust" by pushing those services into the background to let AGH do filtering. The aim is always to make things simple for users as I'm sure you know how tricky getting stubby and unbound was in those early years. I certainly lost hair over it in my trials with OpenWRT)