That's really a bad example. Timers are just standard units that are executed at regular intervals instead of at startup/when a specific file is requested/when

That's really a bad example. Timers are just standard units that are executed at regular intervals instead of at startup/when a specific file is requested/when another service is started/etc. It makes perfect sense for this particular feature to be part of the core capabilities of systemd units. Journald would be a better example but FYI most systemd components are optional and only a few of them are required. Whether it makes sense for those components to be required is up for debate and there are good arguments on both sides. The systemd team decided it made sense to have a hard dependency on those components. You can disagree with them but the only alternatives you have is to either fork, come up with your own init system or join the core systemd team and try to make them change their mind from within (and probably put up the hard work needed to remove the hard dependency on those components). People seem very passionate about init systems since systemd was introduced but few seem passionate enough to do the hard work needed to implement the changes they would like to see.