> The only people that say something isn't genocide are those that support genocide.

I don’t think you meant to phrase it this way. The point in the sibling comment is spot on. If I may, I suspect you want to replace the word “something” with “a credible genocide”.

> broad consensus

Unfortunately, the consensus comes from an unreliable narrator. (That doesn’t make it wrong, just untrustworthy.)

https://en.wikipedia.org/wiki/Manufacturing_Consent

I mean, that's pretty clearly false. Very recently, a certain orange man and his (until this past week) peppy sidekick have been referring to the predicament of Afrikaner farmers as genocide - I'm pretty sure you would agree with me that that isn't the case in actual reality. Therefore, I'm pretty sure you would agree there are some claims of genocide that are in fact false and made for cynical political reasons.

Was dropping the atomic bomb on Japan "genocide"? Was firebombing Dresden "genocide"? We could probably even agree that these were ethically wrong, even perhaps war crimes, but nobody calls them genocide, because they aren't.