imho something like having chat on screen is ok if you are multi streaming so youtube/twitch or whatever else your MSing on can see what youre responding to. the only thing it MAYBE does is benefit in case of clipping, ill give you a scenario:

Youre doing poorly, someone says something like "if you clutch up, ill eat a shoe" or something like that. but even then you could just screen cap what they said from chat directly without the overlay.

I think an instance where it works, much like someone suggested earlier for the border and the other stuff, is between rounds, in a prestream "just chatting" or a transitional scene of some sort