They most certainly were. Unix has been fine being the backbone of the Internet since day one without systemd.

What system that systemd replaced was so bad that it needed to be replaced by the init system.

I am not against new software, but if using a new piece of software, requires replacing dozens of other system components, then something is going very wrong.

The thought process behind people at Redhat who think "We need a new system logger, you know the init system is the perfect place to develop that" is just inexplicable to me.

I believe the only other systemd components required for systemds service manager are journalctl and udev.

for relatively obvious reasons