Watching this is reminding me of my solo-q Zed games (with a lot more CS and mechanical skills), but in general get a lead in lane, and then become useless in team fights.
In season 3 you would just split push, death mark the other guy under tower and have your team play the 4v4. If they win you get drag/baron + tower, if they lose at least you still get tower and create pressure.
However in this meta you're force to back off the split group as 5 and then become useless in team fights unless you're super far ahead.