My thought is that it helps the audience know what exactly they’re doing. Not saying it’s necessary because I think a good visual indication will let the audience know, but I think that’s what they were maybe going for.
I really liked YuYu Hakusho for having big title cards whenever some characters would use attacks (and sometimes equipment/weapons) without yelling. It was also nice that the narrator would sometimes explain things quickly to not detract from the action, though they stopped doing that pretty early on, presumably because they assumed the audience would have a better grasp on things as the show progressed, or because the characters actually had a reason to assess or explain things.
The ol’ Brock effect, a character who’s job 90% of the time was to tell the audience what was going on. More forgivable in a kids show, used to happen way too much in more adult shows too
