The deal is that you’d have to provide the customer not just with a price quote but a complete requirements doc based upon the discovery. They can shop this to other contract houses. Just a bid leaves them I’m the hole with absolutely nothing to show for it.
Back in the day a proper requirements doc was something a client would pay for. It’s a tangible thing with real value.
These days we sell design sprints that produce validated prototypes instead (thank god for Figma). This is a much easier sell and still gives the client the opportunity to decide if we implement the thing or if they hand it off to someone else.
Of course no customer would accept that.