You seem to be objecting to an attempt at defining UBI. I'd interpreted the context as "give me a proposal for how to do UBI", in which case "Social Security and Medicare for everyone" does seem an attempt at such a proposal. The proposal is substantially incomplete, as the question certainly arises of how to calculate social security benefits for those who haven't worked long enough to qualify under existing rules... but with certain answers to that question, it would be implementing a UBI system (along with other stuff as well).
