Most of the OS level resolvers just forward to the resolver provided via DHCP. Which is fine for enterprise, but for home users means using the ISPs resolver, which can track users and has a history of injecting ads on failed resolutions.
Not to mention the user interface for configuring them has never evolved beyond /etc/hosts and the total disaster that is /etc/resolv.conf (on modern linux distros).
The fact that I have to run a separate device such as pi-hole to intercept DNS rather than just point my OS resolver to a blacklist indicates how OS level resolvers have not kept up with the use cases people are asking of them.
And of course, no support for DoH or DoT or even DNSSEC.
Not to mention the user interface for configuring them has never evolved beyond /etc/hosts and the total disaster that is /etc/resolv.conf (on modern linux distros).
The fact that I have to run a separate device such as pi-hole to intercept DNS rather than just point my OS resolver to a blacklist indicates how OS level resolvers have not kept up with the use cases people are asking of them.
And of course, no support for DoH or DoT or even DNSSEC.