Just to chime in here with my honcker experience(s). Honcker is really just a listing agency. This means the dealers submit their inventory along with a price that they will agree to lease the vehicle at. Honcker takes a very small cut, less than your typical broker.
Honcker's main goal is to create a broader leasing platform which will bring in multiple streams of revenue from advertising and the like. Think autotrader, motortrend, edmunds, etc. They hope to do this by streamlining the leasing process both for the dealer and the customer.
For the customer their app presents a clean, easy to use interface with easy navigation and clear numbers on the leases. Most important, they present to the customer a pre-negotiated figure, which is generally lower than prices advertised at your local lease company, and far better than the starting point at the dealership.
The dealers also benefit from having access to a large customer base, which otherwise may never have come across their dealership, or even be completely out of their locale. Having a customer agree on a price beforehand also takes a lot of the hassle of negotiations out of the equation. This is especially true when dealing with a customer who would see through their "advertised specials", and would only be a buyer at a lower price point.
There are obviously a range of pros and cons with honcker(as with any other method). Most significantly, because it's actually the dealer you are leasing from and not honcker, there is always still room for the dealer to play games. If you get a dealer who wants to make things difficult there isn't much honcker can do for you. They are a listing agency not a lease company. Case in point -my personal experience. After selecting a particularly great deal on a lease, the dealer attempted to switch the vehicle from a 2018 model to a 2017 model(!), claiming the original price was for a loaner vehicle that "slipped" into their listings on honcker. I called honcker customer service and quickly cancelled the lease.
Which brings me to the next point. The agreement to lease on honcker is not a binding contract. Agreeing to the price and submitting for the lease is just preliminary. Until you sign all the paperwork from the dealer, you can say no at any time. (I haven't researched the credit check they run and the consequences adequately.)
A few days later I found another deal on honcker which was still about 10$ cheaper a month than the local dealers were willing to go. I submitted, and was approved for it. This time it was very smooth, I chose to go down to the dealership as I had trade in that I wanted to negotiate as well. The lease process went very smoothly, and they gave me significantly more for my trade in than I thought I would get (I had shopped it around for a few months).
In summary honcker is a listing agency not a leasing company. The prices are negotiations from the dealership not honcker. The deals are not set in stone in either direction. It's possible to negotiate a bit more if you found a better deal elsewhere, also still possible to get some dealer run-around. I know there are many other factors, many of which have been previously mentioned. My intent here is just to give some background information on what honcker's makeup and structure really is, to give a better understanding of their leasing process.