You get less control actually. Like you can't even do basic things (capabilities per daemon, limits per daemon, isolation, etc.) with old-school inits. Won't even start on security features allowed to units by systemd.
If by control you mean you can write your own logic in an initscript, then yes you probably can, but it's still limited (never tried runit, but on old rhels and debian they were) by other tooling that expects script to behave in a particular way. You can still obviously do it with systemd by calling your script.