High bronze players (b1-2) are more consistently good than Mid/low silver players

And largely this is not the fault of the players, but is a function of where riot starts your ranked mmr at.

High bronze you've generally got folks who were bronze the previous season but have been improving and are starting to climb out, and occasionally you'll have genuine new players who jumped right into ranked at level 30 and went 0-10 in placement matches and are losing their way down to their true elo (these players usually don't stay high bronze for too long if their skill isn't consistent).

Alternatively, silver is a LOT less consistent. In silver you have many genuine silver players who have either climbed out of bronze or who have been silver previous seasons, but you also have brand new players who got lucky in some of their placements and ended up mid silver, but the real issue is that many people who end up bronze (because thats where they belong) realize that they can attempt to cheese riot's system by creating a new account and re-doing their ranked placement matches, these bronze players know b/c of where riot starts your ranked mmr that if you win 4/10 instead of 2/10 of your placements that you'll probably end up silver to get that sweet border at the end of the season.

I believe riot should start out players ranked MMR at high BRONZE rather than high silver, gold and higher players placing w/ a genuine smurf account would relatively easily win their way out of that elo, players that belong low bronze would fall and end up low bronze and players that are closer to silver would be more likely to end up there, but starting MMR out at high silver creates way too much artificial inconsistency (players at an elo that doesn't match their skill level) and IMO decreases the integrity of the ranked ladder at that level (which intentionally or not, is right below gold level where you get a skin as an end of season reward).