A major flaw of democracy is that, like in all power structures other than, occasionally, inherited monarchy, the people with the most influence are always the most ambitious and hence generally the most ego-intoxicated.
Ego, though, is an adolescent characteristic, useful for competition, genetic, cultural, economic, political. Adolescent thought is necessary but insufficient. Adult thought, altruism, is about protecting the whole gene pool, not just your own personal flourishes.
Rational self-interest does not suffice unless you take a very broad view of what the self actually means.
These thoughts were initiated by a philosophy limerick:
At t, I will be a nonentity
With plans and desires that went to t.
Though I won’t survive,
It’s fine if I strive
For future goods. Who needs identity?