I think unions suppress wages when demand is very high, since they make salary negotiations public making it easier for entire industries to just agree on a sin

I think unions suppress wages when demand is very high, since they make salary negotiations public making it easier for entire industries to just agree on a single salary that don't get out of hand. Pretty simile to the no poaching agreement just that it is now legal. I mean, a union is happy if they can negotiate a relatively "high" raise each year of a few percent, and if they demand more they get scolded by other unions.