The problem in the UK, and many other countries, is that they refuse to split Disabilities in "objectively measurable disabilities" and "not objectively measurable disabilities."

Obviously, you can just objectively measure if someone is fully blind. Sure you can pretend, but that's very hard.

On the other hand there's disabilities like anxiety, where the only option is to ask the patient questions that the patient may or may not have already looked up online.

By not splitting the groups you are left with only two very bad options:

A) Everyone gets a regime with a lot checks and rechecks to keep the system affordable and scoped to people who need it.

B) You give everyone a lax, trusty regime that people will immediately start abusing by claiming they have anxiety or so.