Do you think caseworkers can control these issues? I agree with what you are saying it would take for SEND needs to be met in mainstream. I wish my DS could go to a local school and have friends on our estate etc, instead of in a specialist school 8 miles away. I genuinely believe that could have been possible if Ofsted's requirements had motivated schools to be more inclusive etc. but we are where we are.
And that definitely can't be changed by caseworkers.
I am aware of quite a few local providers that will write reports insisting that a child needs expensive counselling/equine therapy/swimming lessons/LAMDA acting lessons ... That they would be the ones providing.
Don't get me wrong, there will be tonnes of excellent private professionals, I used a private SALT for my DA due to the length of the NHS waiting list but that's quite different from what the pp was describing.
Same with independent advocates, I am aware of some excellent ones in our area and some who are complete cowboys profiting from families in crisis.
I think my overall point is that when people say its simple, or pretend LAs can ignore the lack of resources they are being ridiculous.
When I was a (maintained) special school SENCO we had to admit children via tribunal who really didn't need to be there. And then subsequently turn away children with much higher needs. As a parent or advocate you can just focus on one child, as a school or LA you cannot.
It's just naive to pretend otherwise.