This is really so obvious that it shouldn’t require explanation, but evidently not for some, so here goes. First, most of the staggering cost estimates you see being bandied about are on top of what we’re already paying for publicly subsidized healthcare.
Second, whether the necessary increase in taxes would be less or more than the money saved on private healthcare premiums and deductibles depends upon many factors, but chiefly what your income is now and what you’re paying for healthcare. Some lower income people who aren’t on Medicaid might see a cost savings.
Many people with higher incomes will find that the increased taxes exceed the savings. This is particularly true when one considers that even under a Medicaid For All model, many people who can afford it will still pay privately for better care and quicker access to specialists than the publicly available care.
If you dispute either of these things, you have a serious lack of common sense and should probably see a healthcare professional about this.