That last bit is the real kicker, I think. Under the original proposals, the insurance companies were heavily limited and regulated on what they could and couldn't deny, rate increases, etc. It would have better protected existing, well-insured coverages and prevented the "punishment" the insurance companies enact by penalizing better plans with higher rates. The power of the corporate lobby is strong.
Similar to a universal basic income, I definitely support the ideal of a universal basic healthcare system, with additional coverages and options available at different, pre-set tiers. I'd also love to see a return to lucrative business for family practice doctors, instead of the GP being a machine of cranking as many patients through as possible to maximize billing. Community oriented policing works because it allows law enforcement to integrate with and reflect a community. Neighborhood doctors were more effective in their preventative care for the same reasons. There are studies that help show how this offsets overall healthcare costs, too. So many people go to the hospitals that really don't need to, because they have nowhere else to get their care- which drives up costs overall and limits beds when they're needed for more serious issues.