Difference between old champions and new champions.

I'm a old player of league of legends since the opening in 2009, but because of work i never been in a competitive level, playing only 2 to 4 hours daily (barely 2-3 games per day) i have a month that i come back to the game and i can see a clear difference in overpower between old champions and new champions. New champions basically they all consist in this theme: jump to the enemy champion and blow him up in a fast paste action. A total overwhelming difference between old champion like miss fortune, veigar, ashe, garren, silvir or others that if they enter in the range of the new champions basically they don't have a way to counter attack or defend themselves against new champions fast paste gamestyle. I have been playing for a month now from a 2 years break and i still love the old champions and what i see is that in 90% of the cases where the enemy team is formed by new champions the old champions simply they don't have a chance to win against them, they farm faster, at level 4 or 5 they are already strong enough to kill the enemy champions and they don't give any chance to build your champion since their fast paste skill maintain the old champions always in the defensive.

i would love to hear your opinions and what do you think riot games should do to remove this clear difference between old champions and new champions.