Most animals have only biological needs. Eat, sex, fight for food and territory and so on. When these are met, the animal is satisfied.
Humans have, beyond biological needs, social needs. The needs of social identity.
Social identity – being self consciously part of a group, connected to previous and future generations – was the great transformation which propelled humans beyond other animals.
It also created a task for humans: to deal with the pangs and pains of social identities. Especially the essentially insatiable and intrinsically combative nature of social identity.
Hunger can be fulfilled. Need for acceptance cannot. You eat when you are hungry, and hunger subsides till later. You act so as to be accepted and fulfill a social identity, the need for that acceptance grows and becomes stronger. Fulfilling hunger makes food unnecessary for a while. Fulfilling need for acceptance makes acceptance necessary from then on. Hunger in itself is not addictive. Social anxiety turns hunger into an addiction, a tool not for the health of the body, but for the cravings of the social identities.
The ego is the social self, acting on the cravings of the social identities.
The curtailing of the ego is a necessity for human beings – a way to harness the benefits of having social identities without getting lost in the manic, infinite appetite of those social identities.
The curtailing of the ego is wisdom.