In a time when comebacks are a thing and games last longer by default...

... Why do we still have designated early- or lategame champions?

I've been playing since the release of Jayce and a lot of changes have happened since that time, affecting the pace of the game. From my experience games last significantly longer, especially compared to season two where you could get your Nexus demolished right after the twenty minute mark.

Changes made to snowballing among other things have caused this, mostly to allow comebacks and preventing the game from becoming a monotonous one-sided murderfest - something I approve of, but there are some side effects to this. First is, that earlygame champions have become completly irrelevant. Unless that Shaco racks up ten kills in the first third of the game I can tell for sure that he will have the significance of a stealthed melee minion later in the game. Or take Renekton. Once THE early-game toplaner is now reduced to a somewhat ignored tank unless extremly fed.

On the other hand lategame champs have recieved a massive powerboost with these changes: back then you had to work hard to get to lategame, now you will get into that phase of the game by default and wreck the enemy, no matter what happened before in the game.

Or am I just making things up? Yo boards, help me out on this one!