There is BigBlueButton. It’s more focused in educational usecases (online classes and the like) but it works just fine for everything else. You need to host it yourself, but there are hosted instances out there. I for example use senfcall.
But I think we are talking about different things here. What Chanuk was talking about (I think) is a ms-teams or slack alternative, not a zoom or oracle WebEx alternative. Basically Discord but for business. Sidenote: there is a open source Discord clone called revolt
It’s a term that goes back to the cold war. There was a strike and the Soviet Union ended it violently by rolling tanks into the city. This put communists all over the world into a bit of a dilemma: on one side of the conflict was the working class making their opinion known (a communist value) and on the other the Soviet Union (the good guys). So whose side should they take?
It was British communists who coined the term “tankie” for those who defended the SUs actions to brand them as “fake communists” who are more interested in identity politics (the good guys did it, therefore it’s OK) than the plight of the working class.