As said above, you if you're eliminated, then you're able to spectate them. But what if you're in the lobby and you want to spectate your friends? Well, this could encourage lag, if 40 people spectate the same game, then that could be notably laggy for the other players. How could they fix this? Just add a maximum amount of players that are able to spectate the games. If that's your proposal, then I would be in for it. And no, players can't get laggy if they add a maximum amount of players being able to spectate.