My experience with Medicare is very good. It should be improved on and offered to everyone.
Medicare for all will be, "Medicare for 3 months." It would completely bankrupt Medicare and besides, "Medicare for all" is a really just "single-payer" or the next step to it. And that is the last thing we need. Medicare for all would lead to rationing health care dollars. It would mean that once you spent your share, you're done. Even if you are not healed.
It would mean waiting in line for months or even years as your health issue advances and gets worse and worse and gets more and more expensive to treat. It would mean no private insurance and thus no freedom of choice. It would put the government in charge of your health care.
But worst of all, if the government controls your health care, they control your life. And that means that they can force your compliance to anything they want by simply having the option of cutting off your meds any time they need in order to keep you in line.
If they are willing to murder a baby on the day of its birth through abortion, there is NOTHING they would not do to you. If you are older, you are more of liability in a socialist system because older people have more expensive health problems. If they have no moral compunction about aborting a baby in the birth canal, they will have not problem getting ride of older people who they see as a drag on the system.