There’s this thing called social democracy,
and almost every nation in the world has a social democratic party. The left wing of these social democratic parties tend to be full on democratic socialists.
There’s a good chance that the welfare system in whatever country you live in was built by these social democratic parties and influenced by its left wing of democratic socialists.
Even in the U.S. FDR’s Liberalism has been called “bootleg social democracy” by some historians, and his policies were influenced (though often more as concessions than willing adoption) of the more socialist leaning unions of his time. Even today, the progressive wing of the Democratic Party could be described as social democratic, with its leftmost members (Bernie Sanders and AOC) being democratic socialists.
Liquid breathing is definitely possible, you’ve even done it before (in the womb), but it’s probably not possible with something like blood. I think your friend was probably mixing up two different concepts