By extension, any application or device could rely on DoH instead of OS-provided or network-provider DNS servers. It is controversial, since it both helps individuals combat ISP or government censorship and also helps bad actors do bad things [1].
DoH in Firefox is off by default (at least in every FF I've ever installed). And it's not hardcoded to any specific DNS server, you can use whichever provider you like.
By extension, any application or device could rely on DoH instead of OS-provided or network-provider DNS servers. It is controversial, since it both helps individuals combat ISP or government censorship and also helps bad actors do bad things [1].
[1]https://en.wikipedia.org/wiki/DNS_over_HTTPS#Analysis_of_DNS...