Obamacare is basically based on the Swiss system, so not every other developed country has Medicare for all (even the German system is “it’s complicated”). The main difference between the Swiss system and Obamacare though is the Swiss outlaw health insurance being provided as a benefit at work (so basically no group plans, almost everyone is in the same risk pools). Foreigners living in Switzerland need to document their purchase of Swiss health insurance.
much of Europe force a fixes price table too. Different Insurance companies and private individuals pay the same amount for the same things. That create a even playing field where market forces actually help rather than hurt the outcome.
Switzerland does have mandated universal health care, so essentially the same result as "Medicare for All". It's just implemented in a different form: mandatory basic insurance + supplemental insurance, instead of a single-payer system. A number of other European countries have something similar.