Why do I want to become better than my siblings at the things they are good at?

[DelayedMist]

[Chrysantenum95]

Maybe you knew you are good in those things also and winning the approval of others especially parents gives satisfaction for u. Sibling rivalry never gets old, its common and natural

[AviatorTom]

It's called sibling rivalry. It's very common and perfectly normal, unless it gets out of hand and you try doing something beyond your capabilities.

[RoulOB]

It's competition man.
It helps us being powerful in everything 💪