As long as Motability makes the profit it’s currently making they have no real incentive to negotiate better deals. They have a monopoly with a captive audience which is never a good situation for the people who use it.
This is true.
Car manufacturers will look at the obscene “profits” Motability made during the scandal amid a government enquiry a year or two ago & think “Let Motability use their vast profits/funds to bring the AP down for its users”.