universal streams are very different from clusters and it's never said to consume all of reality. It eats the origins of specific universes (and seems particularly drawn to damaged ones), but in terms of measurable feats the most we saw it do was shake a bunch of universes with its roars right before it/Megatron died. Although the Megatron/Hytherion hybrid seems stronger than the standard Hytherion, as the Alternity had tech to kill those but ultimately weren't able to beat Megatherion.
An annoying thing is to my knowledge what a universal stream is isn't ever clearly defined, but it seems to be interchangeable with universe. The Clusters are the collections of all related universes. Not necessarily just branches, but I mean you know how Clusters work. G1 timelines are Primax and so forth. I haven't found many examples of characters threatening specific clusters often, other than Vector stating he's stopped them from being destroyed before. Given the ridiculous amount of branch universes that universal streams have though, being a threat to an entire cluster would be pretty significant.
Where is this said? I don't really directly remember them being equated.
He does talk about Alternity here and there but we don't really hear from the Alternity or Planicrons directly as far as I'm aware (or at least I can't remember any examples)
Another thing about the Logos situation though: Cliffjumper was not driven insane by it lol
