Just look around if ur not taking damage. I personally dont bother healing flank widows or tracers etc. I main lucio and brigitte in support. I cant reach everyone at the risk of damaging the rest of the team or giving up the objective. Flankers can go find health packs more easily. Brigittes throw is pretty far and doesnt need to be super accurate so its helpful if they are near a ledge. If u wanna flank or snipe thats the risk u take being away from the team. I never play mercy, im bad with her. Feel like this only applies or mercy and ana honestly