It matters that we know how many autistic people there are.
It matters that we know which proportions of them are living in (for example) independently, or with family, or in care homes, or in community with some support.
It matters that we know how many are working, or parents, or carers, or students, or retired, or in need of particular care.
It matters that we know how many of them may also have a learning disability. How many may also have ADHD. How many may also have epilepsy, or anxiety, or depression, etc. How many may need alternative communication methods. How many need adapted buildings, and what generally helps.
In times of misinformation, where anyone can take to social media and publish nonsense in a few seconds, it matters even more that the info is right.
Governments plan, using that info.
Budgets are set, using that info.
Staff are hired and trained, and sent out to do work, using that info.
Charities can plan services around the numbers of people, confident that they have reliable information for funders and for their needs.
Autistic people can begin to feel confident that there's a good general understanding of how many of us there, and what sort of things we might need.
Of course, every actual service for an individual is about meeting that person's own needs, and that will vary. I absolutely agree with that.
But, it would matter a lot if (for example) a school had 35 wheelchair users in its building, and only one accessible loo for use in break times.
It would matter a lot if someone was organising training for learning disability nurses, and none of them were told of the number of people in care settings who are also autistic (or likely to be, but not diagnosed yet), How could they get trained on autism if their management doesn't even know it's a need?
The right information also saves lives:
Autistic people can be put into painful, exhausting, terrifying brain events time after time, day after day, by services and environments that are wrong for them. Fluorescent flickering lighting, air conditioning that shrieks at a frequency that makes a room deafening, staff who turn up drenched in perfumes or aftershaves. I've lost count of the number of times staff have said to me, "We didn't know we were likely to have any autistic people in this service. We never planned for it. It is important? It's just a bit of extra difference, sort of a different personality, likes routine, yes? We can deal with that with no special training, and they'll be fine in the same places as everyone else in the service, honest." (Paraphrased).
The end result is too often those brain events leading to distress behaviour, injury, sometimes death. Brain events appear linked to forms of epilepsy, and that is a significant cause of death for autistic people. It matters that services don't know, and can't plan properly.
We also have a whole multi-£million project set up to solve the 'problem' of the alleged vast numbers of autistic people who are allegedly utterly nonfunctional, and allegedly all costing society over £1 million each. We see paper after paper declaring how those fabricated numbers mean it's better for society that we're no longer here, as society cannot possibly afford that alleged financial burden. How it was unreasonable to expect society to provide extensive care for that many. That pre-birth choices could be invented which will mean parents never need face the alleged horror of a child who (they are told) is certain to need a lifetime of extensive and expensive care, a lifetime in nappies, unable to speak (that's something I've been told repeatedly over many years...). It's utterly horrifying stuff, such finance-based-eugenics-talk. It's resulted in very real discussions about how to erase autistic people entirely. It came from misleading information, repeated often.
Interestingly, when I did some background work on how many people are incontinent, the figure for autism wasn't really any different to the figure for the rest of people...but that's another story...
I campaign hard for the equality and worth of every single human being. I won't have eugenicist policies. Not for autism or anything else. I don't want society going down that path again, ever. But there are others who have no problems at all in viewing people as working-units and saying that if you can't earn X, you're a useless blob who should be erased. Not quite in those words, but that's the underlying message. It denies the full humanity of so many people, every single one a precious and loved person.
So, the numbers matter. They matter for getting the right structure in to support people as and when they need it. And they matter in a discussion about eugenics and the future of humanity. We've already seen too many very wonderful lives extinguished because of near-hysteria over 'cost to society'. Research Down's Syndrome, if you want more info on that.
We can do two things:
Bring to light the full humanity, the full wonderfulness of every human being.
And make sure that people have information that is based on accuracy, not hate, guesswork, ancient data or political spin. Then we can make sure services have the right provision and training, in which they can tailor person-centred support that works.