It is not as easy as that because supply is heavily constrained. You need a lot more people able and willing to become doctors, nurses, people who change bedpans and clean hospital rooms, so on and so forth. Add in aging populations with fewer proportionate working age people, and the equation does not balance.
That is not something any policy change can fix until far in the future. In the short term, all that is possible is deciding who gets allocated the available healthcare.