Zidan kept the show going because he came off as intelligent and charismatic. You can tell how much Zidan was the backbone of the Killstream with the general decline in quality after he left last year.
Metokur brought charisma, bants, and fun to the Killstream. His following helped, sure, but Metokur's presence really helped keep things entertaining.
Andy was the same way, though not nearly as good as Metokur, and he didn't bring even one tenth the following Metokur did. Andy's contributions were the Tonka fight and nothing else.
You could
argue that Zoom contributed because of the bullshit he did against Tonka and Vampkandy, and you'd be right in that. Despite all of us saying "fuck you Ralph for platforming him", a lot of us enjoyed watching Tonka being fucked with, even if we disagreed with the methods. I think more or less we enjoyed watching Zoom fuck with Tonka because it gave us ideas on how Ralph would be fucked with when his time came and the inevitable breakup happened.
In general the power behind the show's success were the targets. Mundane Matt was pretty much despised overall because of how much he tried to supplant Sargon as the leader of the skeptic movement and acted like a snake behind the scenes while screaming about how he didn't believe in gay ops. Kraut was similar, though the gay ops Discord made him worse in the eyes of the Killstream audience until the Boulderstream. Quarterpounder was an absolute joke, but they kept him around as the "token leftist who is also against SJWs", but once he was no longer useful he stopped showing up (which was shortly before the Healstream, when Quarterpounder had his Seethestream telling people to donate to him and not Ralph's charity for St. Jude's). Tonka was the biggest draw because of how much of a beat, baby-backed bitch he was acting, and no one liked him. That's why once the Tonka arc ended it was pretty much over for the Killstream, and Andy and Ralph were trying to save themselves even
before Knoxville by saying they'd do an IRL series which never materialized. Ralph has never captured the Tonka arc or Boulderstream, and that's why he's been lashing out at everyone, seeing who gets his audience more riled up. Right now,
@Null has gotten the most reaction from the Gunt's loyal fanbase, but that's all manufactured shit to begin with and we all know it. At the end of the day, Ralph is monument to all our sins, and he's made it clear that he's taking everyone he can with him.