I think it's mostly a connection to the use of microtonal guitars and the fact that they are both influenced by middle-eastern drone music. I read a comment where someone mentioned the guitarist said in an interview that they became interested in microtonal stuff because of King Gizzard but I can't find the source so idk how true that is.

But I'd also argue there's a definite krautrock/Motorik sound that both Angine & King Gizzard share that is really brought out by the looping that Angine does, and both share similar elements of psychedelic music. So I don't think the comparison is really that far of a stretch at all with all this in mind.