Left-wing has always had a loose, relative meaning, and arguing otherwise isn’t attempting to stop the Overton Window from shifting. It’s just an attempt to gatekeep who gets to be a, “real,” leftist.
No, it’s getting people aligned on terms so proper organizing can happen. Liberals will never align with anticapitalists, for instance.
Right. So, you want to take the term, “left-wing,” which has held different meanings in different contexts over more than two centuries and redefine as exclusively anti-capitalist, so you can tell liberals that they’re not actually left-wing. Now that’s an attempt to shift the Overton Window.
Leftism is revolutionary, rightism is reactionary. Right now, Capitalism is the dominant system being struggled against by Leftists around the globe. During the French Revolution, the proletariat and bourgeoisie both collaborated to overthrow the monarchy, which is why it was left.