other than major cases like airbag replacements, I don't think there is any other brand that would give you any sort of warranty on anything without having to service at their SC.

VWM isn't forcing any customer to follow this policy. If a customer feels that the warranty can be ignored, and have the car serviced externally from day 1, and have all major repairs also done externally at a lower cost, then power to that customer for being able to calculate that the total cost of ownership is still overall cheaper when having everything done externally.

there are competent third-party VW Audi specialists that have the know how, equipment, software, parts etc to completely service and repair just as good or better than SC, it's just up to the customer to decide.