Yes but technology exacerbated them. The great wars of the 20th century killed 10s of millions of people, 10x more per year than any other conflict.
Even ancient wars wiped out whole peoples. Like the Carthaginians.
Man-made climate change is also new experience for humanity.
Maybe, but what about per capita? More people participating equals more people killed, but at the same time i dont think you need high technology to engage in a mass slaughter, swords work just as well.