They're also a thing in Boston and a few other areas in the US. It's blatantly exploitative, to say nothing of the obvious corruption pointed out in other comments.

There was supposed to be a crackdown on the practice in NYC in 2020, but the brokers lobby was too powerful.[0]

One can only hope that such legislation eventually passes -- and has teeth.

0: https://www.nytimes.com/2021/05/27/nyregion/broker-fees-real...