Why is Universal Adult Franchise Important in a Democracy?

It means that every single citizen of a country who has reached the legally defined adult age (in India, it is 18 years) has the absolute, unconditional Right to Vote in elections, completely irrespective of their religion, caste, gender, skin color, or how much money they have in the bank.

1. Political Equality: It legally enforces the greatest rule of democracy: 'One Person, One Vote, One Value'. The vote of the poorest, homeless beggar standing in the slum has the exact same mathematical value as the vote of the richest billionaire CEO in Mumbai. No human is superior to another on election day.
2. True Representation: If you only allow rich, educated people to vote (like in ancient Europe), the politicians will only make laws that benefit the rich. Universal Franchise forces the arrogant politicians to travel to the poorest, dustiest villages and beg the poor for their votes, ensuring the poor get food, roads, and representation in the Parliament.
3. Self-Respect and Dignity: Granting the right to vote to historically crushed communities (like women and Dalits) instantly gave them massive social dignity and proved that the country considers them equal, powerful citizens.