Is fairness a part of Islam?

Is a muslim fair if he: - [He respects elders and not younger people](https://sunnah.com/tirmidhi:1921) - [He has mercy on younger people and not elders](https://sunnah.com/tirmidhi:1921) - He only gives love to the ones he prefer, and not to the people who deserve it - He only appreciates succesful people, and not the ones who excerted the most effort (like all contests I have ever heard about)