I was listening to someone awhile back, I think it may have been Yuval Noah Harari (author of Sapiens) and I don't remember exactly how it was put but it was something like:

"Humans process the world through stories rather than pure facts, prioritizing coherence over accuracy, social bonding over raw data, and meaning over objectivity. This tendency shapes how people cooperate, remember the past, and make decisions." (AI assisted recall)

Now this doesn't make the fact that fellow humans will deny objective facts any less frustrating, but it does explain why it happens. Obviously confirmation bias is heavy at play.