I feel like once you're at a level somewhere close to actual skill, it's much easier to spot mistakes because people will actually punish you for them. For example, players in bronze and low silver will rarely punish positioning in lane. In fact, they probably are positioning in really stuffty spots and taking minion aggro.
If you're positioning poorly vs this elo, you might not even know it because it won't be punished very much, if at all. Then look at G4+ where people will punish it. People either have to learn to position or else they won't get past that elo.
In gold I felt like a legitimate god because nobody punished anything I did. In plat, the non-boosted players seem so much more aware of how to lane and punish mistakes in lane.
Poll