As someone who's been playing since the start of S2.. It wasn't actually any better than it is now. It just cycled through X type of champion being overpowered, X item/mechanic being abusive or just anti-fun, Rengar 100-0ing everything that wasn't a tank in as little as 0.01 seconds, and being near him did not reveal him so he could just walk up to you while invisible and just murder you before you realized he was even targeting you.
Vayne and Kog'maw were basically the only two viable marksmen.
Fiora was able to 1v5 by pressing one button if fed.
Teemo was utterly disgusting to play against.
Tank Ekko.
There were more unpatched bugs, many of which were game breaking, than Mordekaiser currently has.
Feral Flare, Devourer, both made Jax, Udyr, Xin, Trundle, Shyvy all more stat check-y and oppressive than they are currently.
And the list goes on.