I used OpenDNS a while back. I see they were bought by Cisco if that makes any difference. I had not set my DNS since I last installed Ubuntu, so it's using my ISP for now. I may try Cloudflare soon. Had to look up how you set it these days. This site tells you what you are currently using.
Update: Seems it's a bit more fiddly. netplan doesn't seem to like something about the file. Doesn't seem to like the device name even though it looks like it should be right. Oh well, it's a learning experience.
Update 2: Okay, so I can actually configure it in a GUI, but maybe encrypted DNS needs something else installing. In any case my email stops working when using 220.127.116.11. I'll revert it for now and investigate further.