What causes (some) humans' natural tendency to violently reject differing worldviews?

I was thinking about the history of religious conflict in the world. Obviously as we all know, "religious war" has often tended to simply be a cover for something else - war over land, resources, wealth etc which those pulling the strings simply use "religion" as a means of whipping up support among ordinary people who either don't understand or are not aware of the more complex reasons for conflict. However, this doesn't change the fact that it has been an effective tool of war mongering over the millennia.

Obviously, on some level, there's a natural progression from simple disagreement to violent disagreement, even when, as with religion, the difference of opinion doesn't actually have any tangible effects on either party. To differentiate, an example of a conflict which does have a tangible effect would be a property dispute:

Person A: My pint!
Person B: No, my pint!
--There's only one pint, so this has to be resolved one way or another, therefore:
*scrap ensues to claim ownership of the pint*

In the above example, pint can be replaced with pretty much anything, and either "person" can be replaced if necessary with "group of people" - land, oil, water, sex, anything can be fought over for the simple reason that two humans claim it and most mammals will physically engage when territory or ownership of something is called into question between them. And is must get resolved - agreeing to disagree doesn't just mean agreeing to disagree, it also means that one of the parties must give up something they feel entitled to. In my example, one party has to walk away with the pint. If neither of them currently has it, then agreeing to disagree makes no sense because the first one who reaches for it has deprived the second person of something they are "agreeing to disagree" actually belongs to that person, so a confrontation is still inevitable.

What I don't understand is that religion has no such tangible requirement for a definitive outcome, except apparently some sort of psychological one that has no real-world effects. If I say "The universe was created, and is currently controlled, by the Flying Spaghetti Monster" and some other human says "No, the universe was created, and is currently controlled, by the Swimming Garlic Demon", because we're not fighting over a tangible item such as land, property etc that only one of us can possess... What's the advantage or sense in fighting over it?

In this scenario:

Person A: The universe is ruled by the Flying Spaghetti Monster
Person B: The universe is ruled by the Swimming Garlic Demon
[Unknown third step]
*Fight ensues*

The unknown third step is what I don't understand. In example number one, the third step is that it becomes established there is only one pint, and therefore in order for one of us to have it, we must resolve that. It cannot remain unresolved - there has to be a winner, one way or another. But in the latter example, when we're dealing entirely with abstract ideas and not with anything directly tangible, there's no actual reason why we can't just call eachother tosspots for obviously having a totally incorrect perception of the world - and then carry on doing our own thing.

What makes it worthwhile / desirable to basically try to force somebody else into proclaiming that you're version is correct, by essentially using physical coercion and violence to beat them into submission? What are you losing, on a primal or instinctive level, by simple walking away and saying "well, that idiot is wrong, but I know I'm right and that's all that really matter anyway" - my own existence, quality of life, or tangible experience of life is in no way affected by the mere existence of people who believe something different to me, so from that point of view I don't understand the desire, which repeatedly appears throughout human history and is thus not merely an unusual outlier, to physically eradicate the existence or presence of individuals with a different world view.

Tl;dr, why, psychologically speaking, is the natural human instinct in many cases to confront and destroy sources of intangible and abstract dissent rather than simply ignoring them? What psychologically justifies the potentially massive stakes - one's own death, for instance, if the conflict doesn't go their way - in starting a fight about something which in no way directly impacts one's own experience of life?

It's something I've really always struggled to understand. Humans are generally programmed to avoid conflict unless there's some genuine benefit to victory in one, but what evolutionary or instinctive benefit is there in being able to say "I'm right and he's dead"? You don't actually gain anything from it at all, and you've expended considerable energy fighting an unnecessary fight.

Is this something that is known / understood at all?