We probably have different ideas about what constitutes the hard way; but that's not the point in this thread.
Anyway, NetworkManager can be managed using cli for those that insist, so all that was needed was:
nmcli connection import type openvpn file <filename.ovpn>
Even Arch wiki says:
> By default networkmanager-openvpn plugin appends DNS servers provided by OpenVPN to /etc/resolv.conf.
(which is not really true. Yes, it does the right thing with DNS info, but the specific action depends on the resolver backend NetworkManager is configured to use; for systemd-resolved and dnsmasq it configures these services instead).