(a) We have universal healthcare for those without income: Medicaid.
(b) We have universal healthcare for those over 65: Medicare.
(c) Discussing healthcare reform is not considered "far left," there is significant debate about how to do this and how to pay for it across the spectrum. So far relatively left politicians have gotten the most airtime about this, but it is discussed broadly.
Your note reads as snarky and condescending, and then you signed it "Best regards from Germany," which just confirms this is a drive-by European comment.
When it comes to countries that aren't your own, my recommendation would be to ask questions and seek to understand rather than to casually cast judgment.
As a final note, please consider that the US is not analogous to Germany. California is analogous to Germany. The US is analogous to the EU. From my reading of international news, it appears that it's more difficult to work out things at the EU-level than it is at the level of an individual nation. That's useful to keep in mind when attempting to make comparisons between the two regions.