Playing from behind?

Is this even possible anymore? Had a few solo que games where we were downs 6-8 kills, lost map pressure, made a few picks, picked some good fights, and went even or ahead, but it felt like we could never get map pressure back. And even when back to even it felt like fights were still one sided. Is this because of the way minions push that it feels like what happens in the first 10-15 minutes basically decides the game?

Is making come backs harder to pull off healthy for the game?