Using systemd-resolved has some prerequisites - namely
- sync systemd-resolvconf package
- enable and start systemd-resolved service
- backup your existing /etc/resolv.conf
- create a symlink for /run/systemd/resolve/stub-resolv.conf*
- remove openresolv
sudo pacman -Syu systemd-resolvconf
sudo systemctl enable --now systemd-resolved
sudo mv /etc/resolv.conf /etc/resolv.conf.bak
sudo ln /run/systemd/resolve/stub-resolv.conf /etc/resolv.conf
sudo pacman -Rns openresolv