It's equivalent to submitting a lower bid.

(The point is moot though because apparently Uber rolled out a feature that allows drivers in California to set their rates).

A town wants a bridge built. They set a maximum price. Three contractors submits bids. They are all at the maximum price – instead the contractors differentiate themselves based on quality of previous work and distance to the construction site.

A fourth contractor thinks the price is too little and rejects it outright.

The fourth contractor has "submitted a lower bid"?

The fourth contractor submits a bid above the minimum price.

Yes, sorry, I misspoke (edit: actually, I think you misspoke in your previous comment, and then I copied the mistake).

But no, the fourth contractor did not submit a bid at a higher price. They did not submit a bid at all.

Ah yes, indeed I did.

I see your point too. Essentially, rather than contractors proposing prices and then clients accepting or moving on, if clients propose prices and then contractors accept or move on, it's still a market with negotiated rates.