When you bring your vehicle…
When you bring your vehicle in for service, the status of warranty eligibility has not yet been determined. In order for the customer to request that it be evaluated for warranty, they must agree to compensate the dealership for the inspection if the manufacturers warranty protocol comes back and states that it was not covered under the warranty. Dealerships would rather get paid by the OEM than the customer and are incentived by the OEM to do so.
The customer can contact the manufacturer and the manufacturer can request that the dealership inspect it on their dime instead of the customers. However, this would require the customer to file a warranty claim with the manufacturer directly.
This is how all warranties work and it is not different to tech products or sofas. The dealership doesn't manufacturer the car, they simply sell it, just like how Best Buy has an Apple section with Apple Branding. Best Buy can handle you AppleCare repair too, but they need to work with Apple to get approval and if they determine it was customer inflicted damage, Best Buy will ask you to pay for the repair.