afk is a problem needing to be solved, realy
some people might say that you can still win 4v5 yes you can but only if enemy team is allowing you to do so, if they capitalize in any way on your afk you have no chance to get to midgame without losing all the front towers and all the dragons enemy team has one person more meanig that they can basicaly afford having 2 people roaming and killing your team just because they dont need to man up that one lane
its not about winning 4v5 being harder its about playing 4v5 resulting in easy overkill for enemy team