In ubuntu everything should feed DNS information direct into resolved whenever possible.
We are working on improving it, for example in groovy isc-dhcp-client & ifupdown started to do that too.
Unfortunately systemd's resolved's resolvctl is not compatible with Debian's/Ubuntu's historical resolvconf.
Specifically Debian/Ubuntu has a lot of $interface.$suffix where $suffix is arbitrary, such syntax is widely used and not supported by systemd.
So for the time being it is not possible to switch /sbin/resolvconf to be the one provided by systemd.
In ubuntu everything should feed DNS information direct into resolved whenever possible.
We are working on improving it, for example in groovy isc-dhcp-client & ifupdown started to do that too.
Unfortunately systemd's resolved's resolvctl is not compatible with Debian's/Ubuntu's historical resolvconf.
Specifically Debian/Ubuntu has a lot of $interface.$suffix where $suffix is arbitrary, such syntax is widely used and not supported by systemd.
So for the time being it is not possible to switch /sbin/resolvconf to be the one provided by systemd.