As a minimum I believe the dealers should have an equivalent or better vehicle as a service loan vehicle. So many times I have been offered the lowest possible model and specification possible sometimes not even from the same manufacturer.
It isn’t just a recent or Motability thing. In the 1990’s I had an outrageous BMW that cost almost as much as the house I was living in. When the car went in for some work they offered me a Cinquecento https://en.wikipedia.org/wiki/Fiat_Cinquecento
Lets say the air was a nice shade of blue when they expected me to drive to business meetings and park in the executive car park.