Part of it is about outsourcing too. Agencies save you needing to pay for advertising and some level of weeding out of unsuitable candidates. In some jobs companies do little of the interviewing at all and even don't take responsibility for HR.

That would be unlikely in a role such as social workers.

We also pay a fortune to private mental health therapists. Then there are people like Capita for various roles that would have been civil service in the past.

A big question is what is the quality like? Is it worse when through private companies?