It's generally tied to the intrinsic and extrinsic rewards. Most super popular games these days have a short skill ceiling and an accessible skill floor; encouraging getting good isn't a major focus of design.

If all there is to do is to get achievements and better loot, then players will tire and leave.

If there's community, ways to express identity, and so forth, then players will keep each other engaged.

Fortnite doubles down on the latter by having an in-game store with time-windowed products and other mechanics that heavily leverage FOMO and social anxiety.