End of season 5. Teleport meta kept ADC's weak, due to constant threat of ganks from top/mid. Laning phase wasn't as big, since turrets took longer than a minion wave to kill, and people could afford to play weak early game champions. Vision meant that splitpushing was a viable choice in soloq, without getting 5 man ganked from the fog of war. The biggest complaint at the time was the prevalence of Jinx / Vayne.
Season 6. New masteries, so Warlords was OP for a time. Thunderlords. Fervor now. Leaving lane early means losing turret early, and games are typically decided in the first 10 minutes, baring any major misplays from the opposing team. Late game now constitutes having 3-4 items, and a single mistake from one person on either side determines the game. Lack of vision makes immobile picks a lot riskier, and splitpushing nearly impossible. Jinx and Vayne aren't seen in every game now at least. It's Ezreal / Lucian now.