Once I get a good vocal take, I'll double it (copy, paste into new track), both tracks panned center. I'll move the quieter track just a touch behind the master in the timeline, and move it depending on how much spread or delay I want. Usually pretty tight before the air kicks in. Great natural sounding delay and verb without touching a plugin !
Not much reason to resist using a delay plugin to get delay. Doing it manually is fine too but not superior, and using a plugin is more convenient. At least then once you find a setting you like you get a ms value you can use as a guide for the next time. And you can do things like add repeats etc. that would be a pain with copy and paste. Either way it's not reverb.
I find that selecting the right mic is the foundation of a good vocal track. Well, that and a good singer.