Is it possible to have this in-game?

Is it possible to have a live leaderboard in-game, of the players points leaderboard, on a game's page?

This, but in-game: https://imgur.com/a/dvjfF

Technically yes, but it's highly impractical.

You would need to keep track of how many player points each player has in a datastore (you cannot use the playerpoints API as it would take literally forever to get every player and you still need to use datastores, then you need to sort them) . For leaderboards, a special kind of datastore can be used that sorts data automatically: Ordered Data Stores