Not sure if it's a hot garbage, but I don't see why it's better than DoT or DoQ, except maybe a use case for censored countries. DoT is faster and can be abstracted away from from HTTP. Presumably, DoH is more privacy preserving, because it runs on the same port and looks just like the rest HTTPS traffic. But I think a spying ISP can probably guess that it's a DNS traffic by where it's going. If it's an HTTPS connection over 443 going to a know DNS server, then it's probably a DNS request, thus I don't see added privacy here.
But from traffic administration, it is harder. As a an example, now your Smart Spying Device can phone home and it is going to be harder to block it.
Also, we are moving from your ISP knowing too much about you to Cloudflare knowing too much about you. It's one of the biggest DoH DNS services, often they see unencrypted HTTPs traffic, they also an exit node for iCloud Private Relays. ISP is left out, but Cloudflare seems to be able to consolidate this knowledge.
