Just because you are more educated about ww2 than other wars you seem to think it's worse.

Nope. I'm educated on many wars throughout history. My assertion has to do with demographic, logistic, technological, etc realities. Human beings are now more concentrated, we have infinitely more destructive weapons and due to mass media/propaganda, entire nations can be brainwashed into advancing towards a particular purpose. These characteristics are not something that existed in wars of ancient history.

If you look at atrocities and war crimes committed in our past we were much more savage and cruel.

Not really. You think humans were more savage and cruel because you don't know history. Humans are human. People's nature didn't change. We are just as cruel as our ancestors. The only difference is that we are now well fed and content. When that changes, we turn into our true savage selves. If you think anything in history was worse than the atrocities committed in the 20th century, then you don't understand modern history.

Now we have more efficient weapons yes, but as a species we're slowly moving toward peace.

No we aren't. our military isn't "pivoting" to asia because we are moving toward peace. Military spending is increasing around the world not because we are moving toward peace. Japan altered their pacifist constitution for a reason. NATO is expanding eastward for a reason.

There will be less major wars, but the major wars will be incredibly destructive. Only the naive and childish people without any understanding of history and human behavior think that the "species" is moving towards peace. We aren't developing better nukes, better carriers, better fighter pilots, drones, laser weapons, etc because the human species is moving toward peace. The chinese aren't developing satellite destroyers, carrier destroyers, nukes, etc because humans are moving toward peace. The russians aren't annexing crimea, fighting georgians/caucasians, militarizing sakhalin/kurils, etc because we are moving towards peace.