Top should not be a solo carry lane, but when top, mid, and jungle are all doing well but bot lane is two levels behind their enemies and that means gg, there's a problem.
Top SHOULD be the wildcard in games. It's the role no one else is paying mind to, so it can result in some serious swings in early fights if they TP or Shen/Gangplank/similar ult when they have the 3-4 level advantage over the other lanes.
Or at the least going even top and helping mid dominate their lane while getting the jungler fed should amount to SOMETHING. Even as a lanebully/early game champion like
or
, even and especially if games go long, they should have a real impact in their game outside of setting the enemy top laner back for the first few minutes. Because they can get ahead, their level advantage should mean they can hop into the other lanes and extend that lead in those ones. Instead of needing these characters to win the game before 20 minutes, they should be able to take their won lane and use it to get their scaling midlaner or adc on the right foot going into the later stages of the game.
But no, even if you go out of your way as a top laner to help your bot two or three or four times, it won't matter if they are just the worse ADC player, you're team will more often than not lose just because the impact that single role has in the game.