Its raison d'être is largely to mitigate the issues that limited DoT's (DNS over TLS) widespread adoption, specifically "Middlebox Bypass."
Meaning if you connect to a public WiFi network, many will only allow captive DNS and block other protocols including DoT. DoH is difficult to distinguish from other HTTPS traffic and is more likely to successfully resolve (since they cannot block HTTPS and still be useful).
Therefore you've created a secure, flexible, and reliable DNS replacement with only mild technical downsides on modern hardware (a lot of the complaints are ideological or relate to specific incompatibilities with existing solutions like the lack of HOSTS file support in the initial offerings).
So I guess, everything I just said is "the point." Rather than trying to use every single possible combination of HTTP headers.
Meaning if you connect to a public WiFi network, many will only allow captive DNS and block other protocols including DoT. DoH is difficult to distinguish from other HTTPS traffic and is more likely to successfully resolve (since they cannot block HTTPS and still be useful).
Therefore you've created a secure, flexible, and reliable DNS replacement with only mild technical downsides on modern hardware (a lot of the complaints are ideological or relate to specific incompatibilities with existing solutions like the lack of HOSTS file support in the initial offerings).
So I guess, everything I just said is "the point." Rather than trying to use every single possible combination of HTTP headers.