DNSCrypt and other solutions typically involve changes to the DNS resolver in the underlying operating system. That's a lot harder to get changed and deployment can take a long time.

DOH can be implemented directly inside of the web browser application, since those browsers are obviously already doing everything over HTTPS. So the browser developers just have to build in a DNS client. From their perspective, I would see that being much simpler. And deployment is as easy as the next browser application update.

DoH has already more adoption than all previous approaches combined. (Note: I don't think DNS-over-QUIC is really any different from DoH. QUIC is just another way of transmitting HTTPS, so you can just do DoH over QUIC.)

DNScrypt is easy to block, therefore it can't further the privacy-for-all cause.

Because DoH is really all about serving ads, no matter what.