People ARE fundamentally selfish in any groups above 150-200 where the social net breaks down. Most groups of animals don't stay group-serving in giant groups, we are no different.[1] In groups small enough to be inside the social net, tribe survival dynamics work great.
> things were bad, then society developed and now things are better”
Things are not great. Technology makes them better though. Man can't easily escape technology today, but it is the fundamental trade-off society offers at the cost of social health.
[1] https://search.brave.com/help/privacy-policy
Edit: mojeek claims the same.[2]
[2] https://www.mojeek.com/about/privacy/