A single-payer system would take the insurance companies out of the process. They are getting rich on our current ineffective system. It would also allow the government to exercise heavy pressure on drug companies to give us drugs at the lower prices they charge in other countries. (That's why people go to Canada to refill prescriptions.)
You are living in a fantasy land. Insurance companies will not go out of business in a single-payer system. They will be incorporated into the system as administrators. They will still make plenty of money since they will taxpayer funded. In fact, it will be worse because they will be removed from the competition of the free market.
Drug companies? They will put more effort into areas like palliative care. The motivation for R&D will be removed.
Let me school you on economic 101. Once the free market has been removed from ANY industry segment that segment becomes part of the government bureaucracy and begins to atrophy. The federal government never does anything efficiently. NEVER. It does not even collect taxes efficiently.
Single-payer will also exasperate the economic divide between the rich and poor. Those with money will bypass single-payer and pay doctors and hospitals directly. In the quest for health care fairness, the American consumer will receive just the opposite.
Then there is the matter of availability. Once people are covered from soup-to-nuts, at zero cost, they will use health care more. The strain on medical professionals will be overwhelming. Medical professionals will have their earnings capped as a way of managing costs. The government will also try to cut costs by denying certain medical procedures. This will have the unwanted effect of denying essential services to certain people. Wait times will lengthen. Litigation will increase. Sure. Insurance companies try to cut costs too through "managed care". The difference is that consumers can sue health care providers, and often do (successfully). Try taking the government to court when they hold all the cards.
Instead of socialism, why not fix the free market solution? Allow Americans to purchase insurance across state lines. If taxpayer money must be spent, incentivize creative free-market health care solutions. Encourage more concierge or fee-based health care memberships where patients pay a flat fee to receive most primary care physician services. The free market can solve most of these problems if it is allowed to do so.
And what about those that are truly poor and cannot afford healthcare? We take care of them. That is right. We do not kick them to the curb. But we do not allow the minority to dictate to the majority. In other words, we do not adopt socialized medicine because a minority of people are uninsured. We adopt different solutions for those in need.