"Technology adoption will be a huge part of managing the cost curve"

Just tell people they're getting robot nurses before single payer healthcare.

The problem we have now is that there is no accountability in spending. Insurance companies over-charge for everything.

Single-payer just exchanges the insurance companies, for the government. There's still no accountability on cost and there's the added bonus of turning you down for life-saving care, if they feel you don't need it (there are many examples of this in the UK).