[kijin]

> most users are not going to be savvy enough to find those IPs and use them.

Very few people configure DoH on their own. It's up to the DoH-enabled client software (mostly browsers) to obtain lists of resolver IPs and keep them up to date.

If Cloudflare, for example, really wanted to make their DoH traffic indistinguishable from other HTTPS traffic, they could literally host DoH on any domain or IP under their control and rotate the list every now and then.