Having had the joy of writing code to manage system wide DNS config for all 3 of the major desktop operating systems, it's very clear that nobody cares about DN

Having had the joy of writing code to manage system wide DNS config for all 3 of the major desktop operating systems, it's very clear that nobody cares about DNS - the users just want it to work and the systems developers also just want it to work. On macOS, if you don't have an IPv6 enabled primary adapter, even if you have a working IPv6 VPN connection, you just won't be able to get AAAA responses regardless of your configuration. Watching for config changes is also a race ridden mess, applying DNS on Linux on major distros is also a crapshoot of which specific NM (NetworkManager) version the user is using (this can differ between a fresh Ubuntu 16.04 install and one which has been upgraded to 16.04 from 14.04), and which specific DNS mode NM is configured for. There's also systemd-resolved, with multiple versions and capabilities, and there's also resolvconf. In some cases, there's a notion of a global config, in others, the config is always bound to a specific interface. Windows is somewhat better in this regard. But at least the developers of NM and systemd-resolved are receptive and incredibly helpful.