If you're saying that the historical "broker's fee" when renting in a place like NYC doesn't benefit you, then I agree. That broker represents the landlord, not you, and you're just being charged to make up the cost.

If you're saying that someone doesn't "work for you" unless you pay them a flat or hourly rate, then I disagree completely. All incentive structures have problems. Someone who works on contingency is incentivized to get you to sign. If they take a percentage cut, of course, they want you to sign the most expensive thing they can. Someone who works on a flat-rate basis is incentivized to do as little custom work as possible. Someone who works on an hourly basis is incentivized to drag out the proceedings. There is no perfect system.

Most of these agreements are structured where the fee is paid by you, after signing a lease, as a function of the monthly/annual rental price. The agent works for you, you just don't pay up front or a fixed cost or on an hourly basis. Does this change the incentive structure? Yes. Does it mean that they don't provide you a benefit? No. You just have to be aware of the incentives.