Only the company knows how well they will be able to turn work into the money that they can use to pay the worker.

The candidate can show the ability to do whatever work the company may require, but if that work does not increase revenues in some way, it will not be able to keep the worker employed indefinitely. Obviously, there's a lot of room for speculation here.

The worker has a general idea of the average amount that many other companies might expect to value the work of similar workers. So the prospective employer has to signal that it can monetize the work more effectively than the median company to attract better than the median quality of candidate.

If your company is building yet another CRUD business app, you do not need above-median skills, nor could you afford them. If your company is building a new, Wall-Street-killing trading platform, you need the 99th percentile of skilled workers, and should therefore be offering 99th percentile pay, because the work will eventually be worth billions of dollars.

The candidate knows how much their labor is worth on the open market. If the prospective employer does not know how much the open position's work will be worth to the company, it really shouldn't be trying to fill it until it does know. If you want to reach the higher-quality candidates, you have to send a clear signal that they will not be rejected for wanting too much money, which happens all too often with companies that need to pinch their pennies or extend their runway.

There are companies out there that will hang up the phone if you say $100k. And there are also companies out there that will struggle to hold their poker face at being offered such a great discount on an employee. You won't necessarily be able to determine which is which before you apply.

When the company does not say up front, it is implicitly saying "we will pay you exactly what you are worth, as determined by negotiation, with no predetermined limits." If they wait until halfway through the second phone screen to bring it up, and then say, "that's more than we can pay", they are wasting the candidates' time.

That is why the company should lead with their salary maximum.

The analogy is not a fixed price on fungible goods in commerce. The candidate has a unique artwork, to be sold at auction. The auction house would very much like to establish that potential bidders have at least enough money on hand to meet the prospective employee's reserve price before giving any of them paddles, especially when the bidding procedure can last several weeks per bid. The candidate does not want the reserve to be known, as they would prefer to get a higher price. Likewise, the prospective employers do not want their maximum bids to be known to their competition. But as they can only complete the purchase by making the highest bid anyway, their wishes do not matter one little bit. You have no business bidding on a Van Gogh painting with only $5k in your pocket, looking for something nice to hang up in a hotel room.

The employer is the one that makes the offer. They are selling the pile of cash, and the employee either buys it with their labor, or leaves the offer on the table.