Many Alts. What do you concentrate on

Hello there

I, like quite a lot of you here probably have more than one character and across both factions too.

My main is a lock who is raiding and Is progressing in Antorus. However what to do with all my alts. Every class is covered and more than one of some of the classes.

Do you gear all your alts to end game raiding level and raid with them all, or as many as you can raid in a week, or only concentrate on a couple and leave the others to gather dust. Just trying to work out if a tank, a healer and dps specs should be covered. As I enjoy all classes; just better at some than others.