Let's first address all the "nature" and "biological" not-really-true claims.

The Batek people of Malaysia are so averse of killing other humans that refuse to do it even when threatened with slavery https://peacefulsocieties.uncg.edu/societies/batek/

So, war is cultural, not biological.

Second, why do we do war?

At first glance, is for scarce resources, for survival.

But look at the modern wars. Are they for survival? Are they for resources that we need to survive?
No they are not.
They are for power.

But whose power?
The power of those who actually have to fight and die?
Certainly not.

The power of the rulers, who are greedy for more power.

Most people need to be scared into going to war, need to be convinced that they are defending their families and their "people".

This is why rulers work very hard to build national identities, the good "us" vs the evil "them".

Here we need three things:

1. We need a culture that knows how to recognize those greedy for power, those with a desire to dominate, and see them as the threat to freedom that they are, ie some sort of https://en.wikipedia.org/wiki/Leveling_mechanism
   There are several cultures that do that, but it has to be a deliberate and conscious thing.

2. We need to rethink our identities, national and not, because those identities are used to define the "other" that is ok to harm and kill.
   A way to do this is to make sure that people who want to travel and visit other groups can do so easily: this will help the various groups understand and humanize each other.

3. We need a culture that stresses the importance of non-violent conflict resolution.
   Because if all you know is violence, then that's what you will use.

I mean, easier said than done of course, but I think that knowing the direction makes it easier to reach it.

For further reading on the subject, I would recommend Bob Altemeyer's "The Authoritarians" and Graeber & Wengrow's "The Dawn of Everything" from the top of my head.

You may want to read some anthropology before you decide that war is a biological imperative.

You are mistaken, and if I were you I would have a long hard look at the kind of sources you consume, because they are manipulating you and feeding you false information.

It was very hard for me to accept the idea of privilege, but when I started taking the idea seriously, a lot of pieces fell into place.
In general, being exposed to actual feminist material (rather than whatever sources you seem to use) was incredibly liberating for me as a man.

Now.

The opposite of "toxic masculinity" is not "no masculinity", it's "healthy masculinity".

And a big part of learning healthy masculinity understanding how privilege works and learning the difference between guilt and responsibility.

As a man, you (or I) benefit from a social system that more often than not puts men in a position of power over women, and this is what usually people mean when they say "patriarchy".

You are NOT guilty of being a man, of course.
You are NOT guilty of setting up such a system.
In general, you are not "guilty" of the circumstances of your birth.
But if you spend your effort to ensure that this system (however you personally decide to call it) keeps going on, then you start to be a bit guilty, yes.

Now, "responsibility" is a different thing.
Because you (and I) are in a position of power, and we have a responsibility to use that power, to use our privilege for good.