you install a distro because of all the software it includes and how they interact out of the box

you’re completely right that systemd is a background service that most people don’t care about, but it does make the whole system more reliable, and much easier to administer for servers or workstations (enterprise management; not personal)

you certainly do want an init system… even sysv-init is an init system: you need something that runs as pid 1 that triggers other services. systemd starts services, and also ensures they’re in the correct security contexts, running as the correct users, makes sure they’re healthy, tracks dependencies (not just order; this speeds things up because it can be parallel, ensures failures don’t cascade, and means there’s far less jank in random bash scripts)

this isn’t a big political statement: this is an acknowledgment that linux users - not all, but some - will want/require something like this… and systemd user database is the place where that information is stored on modern linux systems