My personal theory is that humans still have the same instincts and traits of humans many centuries ago that don’t benefit us in modern times. We evolved our environment and now we have things such as the internet, but new medicine and QoL has hindered our evolution.
Things such as anxiety aided in our survival back then but now it only hinders us. We live a totally different lifestyle and our bodies and mind are behind.
Hopefully in the future, we can find a way to fix ourselves and then we can live peacefully.