You're correct, but you're acting like the standard is a decision making entity. When a calibration lab is contacted for service the explanation of services is clear. The calibration lab doesn't then look up the client, decide what standards to apply randomly, and then perform the calibration under what they think best suits the client's industry. It just doesn't work that way.
You also keep placing bold emphasis and italics on this part that fits your narrative:
" the laboratory shall be accredited to ISO/IEC 17025 or national equivalent and include the
relevant inspection, test, or calibration service in the scope of the accreditation (certificate); the
certificate of calibration or test report shall include the mark of a national accreditation body;
The alternative is to go to the customer. "
OOPS - looks like you stated yourself that the alternative is to go to the customer.

there shall be evidence that the external laboratory is acceptable to the customer.
Just like Jim Wynne stated above - there is an "out" here that there may be a case where the calibration cannot be accomplished under ISO/IEC 17025. Why are you still arguing against the standard, which clearly states this?
Also I'm not in the "kitchen", nor am I part of an IATAF regulated organization - I am, and have been for years - been involved in ISO/IEC 17025 calibration laboratories.
I am making those statements based on your accusation of an accredited calibration laboratory "cheating" a customer that requests work outside the scope of accreditation. I'm not arguing the IATAF guidelines - you made a straightforward statement that contradicts services offered by every major calibration laboratory in existence. Even FLUKE does calibrations unaccredited, for god's sake.
Story Time:
Man goes to restaurant. Asks for the daily specials. Burgers pickles (NIST Traceable) $3.99, Burgers with all the fixin + fries (NIST + Uncertainties) $4.50, or the Ribeye special (ISO/IEC accredited) for $9.99. Man chooses burger and places order with staff. Staff delivers a burger as promised; however, the man argues he should've received a Ribeye, as Ribeye was offered on the lunch specials. Staff explains he chose and paid for a burger.
In your world that is "cheating" a customer? Or should that customer know what they want and what they want to pay for said service?