Gamerscore is the cumulative point total from unlocking Achievements across Xbox games. It serves multiple purposes for players and the platform.
Gamerscore is a toy metric. It doesn't measure skill, intelligence, or worth. A 500k GS player isn't "better" than a 5k GS player who only plays Elden Ring and Baldur's Gate 3 once each.
Use it to track your journey, discover new sides of games, and connect with friends. Don't let the number play you.