A “move in” fee is not a deposit. It’s more like a goodwill payment, or you could call it a front pocket fee, even if there’s nobody else in queue. Obviously whoever is willing to pay the most gets the first choice.

It’s shady as fuck and also illegal where I live, but people still pay it instead of risking not getting the apartment. Sadly, nobody cares enough to take these scumbags to court over it. You can choose not to pay it but then you just don’t get the apartment, and if so, why’d you want to waste your time and money on a lawyer, when there’s nothing to win from doing so.