It's due to systemd in that systemd makes it too fiddly to figure out or change which services are enabled on boot. (I used to know a way to disable certain services on boot under systemd, but it doesn't work any more, and I've reached a state of learned helplessness at this point)

`systemctl disable` and `systemctl mask` work today just like they worked decade and half ago.

I don't know if they're the recommended way of doing things today, but they weren't what was in the manual when I was learning.

They are there from the start and were always the recommended way to do things in the documentation. I mean the command is literally disable.

The command to list services enabled on boot is also completely esoteric: systemctl list-unit-files --state=enabled