What is the difference between using NextDNS in Android's Private DNS and Rethink?

If I use NextDNS via Android’s Private DNS, it’ll use the DoT profile. My understanding is that all DNS queries, whether it’s from the web browser or system, will utilize NextDNS. I know Rethink can use DoH, but other than that, any other difference?

I just downloaded Rethink to my Pixel with stock OS and am slowly learning how to use it. I’m more interested in the firewall feature than the DNS feature since I’m already using NextDNS. Any reason to use Rethink’s DNS other than everything is on-device?