If Rutger Bregman knew me, he might be surprised to learn that - with reservations - I agree with his contention that most people are basically decent and kind. My objection is that common decency and kindness are not enough, and Bregman himself reveals some of the reasons why that is so.
In discussing Stanley Milgram's shock machine research and even the case of Eichmann, Bregman argues that most people are trying to do good - 'do the right thing' as we say - but can be misled into doing evil. One aspect of this paradox emerges implicitly with Bregman's comments on wartime bombing from 1940 onwards. Indeed, Gustave Le Bon was wrong about how people behave in a crisis (as distinct from a brief panic); they pulled together, helped each other, and became more effective in the fight. But the presence of a common enemy made immediate by the bombing was needed for that effect.
On the broader theme, if the appearance of agriculture and political organisation (in the case of Egypt because of people moving into the Nile valley as the Sahara became desert) was sufficient to plunge us into wars and oppression for 10,000 years as Bregman claims, it should be clear that maintaining the good life takes more than ordinary decency. The status seekers in modern Western societies as well as family or clan feuds in pre-modern societies show that corruption of spirit is not confined to the holders of great wealth and power.
Like Bregman, I have no view about whether it will be possible to recreate some version of of the hunter-gatherer lifestyle in the future, but there is certainly no guarantee that would be possible. Moreover, in many cases we need the technology civilisation affords to give us the awareness compassion requires, especially from a distance.