They are now having to onboard two people whereas their original agreement with you only required they do this once. It’s not like the person they hire after you (which is extra work for them in itself) is going to be able to begin real productive work on day one; they’re going to need logins, learn procedures, setup tax and payment stuff, learn the details of the project and finally learn where you left off and how they plan to finish. You bouncing costs them money and put them behind schedule, plain and simple.

they’re not cutting boards, theyre charcuterie boards.

Because small variables can wildly change costs? Because generating a quote based on all pertinent information IS work, and has value. I make signs. A lot of times I will measure someone’s sign for free because I want the job and need this information to generate a quote - so I do this for free, include this info on the quote, and the customer takes the quote to another sign company who now has all the info at my expense.