I mean it isn't. Progressivism only seems to exist as a word in America, because the USA has the red scares, and conflates communism and socialism, and so are scared of the phrase and had to reinvent their own.

In Europe, you have Conservatives (right wing market, socially conservative), Liberals (free market, but with positivity towards social reforms). Socialism or Democratic Socialism (positive social reforms, state involvement, but with democracy). Communism (economic distribution but more autocratic), and Social Democratic (somewhere between Liberal and Democratic Socialist). Socialism is where you're willing to consider the state getting involved in wealth redistribution.

It's better you understand political philosophy and how it is used and applies around the world to truly understand it. You cannot understand the spectrum, if you cannot zoom out from the Overton window.