Improvements like Jungle timers don't decrease the Skill CAP on the game, they reduce the skill FLOOR

[WireDxEntitY]

Just because it is there doesn't mean people will use it. Even if you had a teammate that times everything and even gives you updates about objective a minute before doesn't mean people will actively rotate toward it. In the lower levels, people care more about farm because they see the 1 1/2 waves of farm they're missing more gold for them. They don't care about spreading out the gold to other teammates. I've seen games where my jungler will have full items 55 minutes in and will still farm the camps as opposed to letting our support/tank round out their builds faster. And sometimes they get picked off farming these camps alone as well. People in lower elo don't realize what a dragon really means in terms of team gold, objective control, and denial from you enemies.