With networkd, we would no longer be able to DHCP-assign Nintendo 3DS nor Apple iPod nor deal with Juniper's DSL (by ISP) concentrator nor deal with a "he-shall-remain-nameless" residential alarm provider.

DHCP OPTIONS feature (that systemd-network does not have) still has major places within enterprise and homelab networks.

Example of Nintendo DHCP Workaround using ISC DHCP: https://github.com/egberts/isc-dhcp-server-nintendo

So, excuse me while I vehemently resist systemd-networkd.