i think the solution to such a thing would be the implementation of a couple of rules, if someone dcs and after 5 minutes that person doesn't come back you have the right to surrender immediately, nobody would be having fun at 4 v 5 anyways, and also the fact that the team with the dc if they lose they don't lose lp except for the one who left, whom should lose double, this way the affected losing team still has an incentive to report the afk for wasting their time without all the rage of losing elo and lp.
please give feedback on the matter, we need something like this cuz every V tier of every league is full of afk dc and trolls due to the fact that they lose nothing...