Single payer would allow all outcomes to be evaluated in total per year, so we could see better which things work and not, and what are the best return on spending. Big medicine doesn't want that, nor an FDA that has to consider budget implications of approvals. The ways single payer would help is by reducing friction in getting care, much less time with any approvals. And everyone would need less liability coverage if health costs are covered. That can lower automobile, business and other liability insurances. Everywhere else does it for less of a share of their own GDPs.