Except that it wasn't a credible alternative.  There was the benefit of providing pressure for a stronger welfare state and greater income equality, but in states where the communists were powerful it made it much more difficult for the left to come to power.  Think Italy, or even France where a straight left wing government didn't get into power until 1981.    Furthermore, the existence of communism provided pressure for increased domestic repression.

I think we do progress a disservice when we reify the concept of democracy.

Here I really think that there is no credible alternative.  A non democratic state, by its very nature has to engage in a greater degree of domestic repression to maintain elite power than a democratic one.  In an authoritarian state, even a left wing one, all of us would either be keeping our mouths shut online, or we'd be on a path to jail.  Workers would have even less right to organize and strike than they do now.  The right to public protest against government policies would be gone.