I don't knit, but none of those do what Discord does, really: effective group chat + in game voice. Skype is sort of is in that direction, but Discord's UX nails it for in-game chat whereas Skype's did not. (Though it has been a while since I ran Skype for more than "oh, that's the only medium that party supports? I guess if we have to…")

I do feel that these apps these days, Discord included, eat a ton of resources, and that it feels like a regression.