Not everyone disabled is entitled to PIP (the majority are not). Not everyone entitled to PIP claims it. Why would you put yourself through that humiliation if you didn’t have to do so? And not everyone who does receive PIP gets the same amount of money. Some is for care needs, some is for mobility needs, and there are different rates for each depending how significantly the disability restricts the person from basic tasks like washing, eating, dressing, or walking.
Only those who are entitled to PIP AND claim it AND have a disability that impacts their mobility AND that disability impacts their mobility so severely they receive the highest rate of mobility payment are eligible to use the mobility part of their PIP (PLUS £X amount of their own savings/ earnings depending which car they choose and how expensive it is, i.e. they pay the additional cost of a more expensive car themselves and it doesn’t impact the taxpayer at all) to lease a car through Motability.
It is, therefore, obviously quite ludicrous to try to compare the total number of people in the population who have some kind of disability (defined in law as a long-term health condition persisting for over 12 months which impacts their daily life) with those eligible to pay to lease a car through Motability, who are a tiny proportion of the people who have some kind of disability: those who have the most severe mobility issues and can only walk very short distances (or not at all) or live in chronic pain.
Their use of the scheme or which car they choose to lease if they do so makes no difference whatsoever to the amount paid as disability benefits. If they do not choose to lease a car or mobility scooter they will receive the same amount in cash instead of using it to pay a Motability lease, so that they can instead lease or buy a car or scooter privately or pay for taxis, etc.
There have been some problems with criteria allowing people with significant mental illness such that they are a danger to themselves or others if walking/ using public transport to access the scheme, which some people reportedly have been abusing.
The answer to that is more stringent evidence being required to claim for mental health conditions, not restricting the choices of disabled people to choose to use their money to lease a car that best suits their needs or that they simply happen to prefer, given it has zero impact on anybody else. Why shouldn’t they? They are the ones funding it with money which is theirs to spend as they see fit.