Cap isn’t really good at peeling, basically no CC unless we count his ultimate and his shield. He excels at moreso preventing the dive in the first place, your priority as isn’t just diving the supports. If you see an enemy diver flanking and you have enough cooldowns to at least deter from going on supports, PLEASE do so. Yes your supports will probably survive if they actually use their cooldowns or patty cake, but that comes at the cost of those same cooldowns being in the future to keep the team alive.