DNS over HTTPS is immune to amplification attacks.
If the alternative to DNS over HTTPS is a DNS-over-TLS resolver being run by a company without a website (???) then I guess that's easier than DNS-over-HTTPS. Are you really going to use a resolver run by a mysterious nobody?
There are probably more than a dozen HTTP stacks being widely used in production. It's not remotely a monoculture.
If the alternative to DNS over HTTPS is a DNS-over-TLS resolver being run by a company without a website (???) then I guess that's easier than DNS-over-HTTPS. Are you really going to use a resolver run by a mysterious nobody?
There are probably more than a dozen HTTP stacks being widely used in production. It's not remotely a monoculture.