You don’t need to depend on others to grant you legitimacy. You stand on your own two feet; you grant yourself legitimacy.
Why depend on others for your own legitimacy?
Legitimacy — law. (Lex-) as the law.
We lack the morality to define our own self worth?
Christian morality says:
Thou shalt not posit thy self worth.
Your self worth will always be seen on the ledger of someone else.
Why do we use numbers to measure and weigh self worth?
Social media numbers, likes, views, followers, 0’s and commas in your bank account, your title. Perhaps it is because we currently are living through the cult of science and the “quantified self” movement. I see this as very bad.