The point is that the replacements being talked about, systemd-resolved for dns, systemd-timesyncd for ntp, and systemd-networkd for whatever else you would prefer to use for network config, are not a mandatory part of systemd. You can use systemd without using these other components and it will work perfectly well with whatever other services you want to use for dns, ntp, and ip networking. These other services are not dependencies of GNOME, either.

People are conflating systemd itself with all the optional services it comes bundled with. I don't even believe resolved and networkd are enabled by default, at least not by the vendor. Whether a distro enables it depends on the distro.