Bernie Sanders gets called "far left" or "socialist", but if he lived in Europe he'd be considered a pretty run-of-the-mill centre-left liberal.
Here in Czechia, the most socially conservative party are christian democrats, who are center-left on economic issues, another very socially conservative party here is the (far-left) communist party,
Bernie Sanders views on healthcare and taxation would not be considered center in Europe. You’re repeating a ridiculous meme. Are you American?
I consider Social Democracy to be a rather confused ideology. But in Europe it is immensely popular. What is probably different is that capitalism is extremely popular in Europe, and in many ways Europe goes harder on free markets than even the USA, even trying to solve the climate crises with some capitalistic cap-and-trade scheme (Americans can think of western Europe as an extreme version of California).
In the USA, capitalism is only popular among the rich (and subsequently politicians). Politicians on both sides of the aisle are more focused on social issues (as are voters) so capitalism remains an unasked question when it comes to the polls. When you talk to a random economically informed working class person in Europe, chances are they favor capitalism. In America however (at least on the West Coast where I live) you’d be hard pressed to find a working class person that likes capitalism. However in the USA the social issues are so glaring that most voters seem to be OK with voting for a capitalist just to prevent a fascist getting power. In Europe this would be unthinkable.
This is why it is actually a bit confusing to put Bernie Sanders on the European political spectrum, because in Europe he actually would be a run-of-the-mill politician (albeit a bit left). In the USA, he is spectacular.