It is always correct to give your main characters the most random interests. Does it add anything to the plot? No. Does it match a stereotype? Not really. Is it something predictable for their character archetype? Nope. But is it fun and does it make the character feel 100x more realistic? Aboslutely.
The easiest way to make your characters more fleshed out is to give them interests and hobbies that have zero bearing on the plot. That character who is supposed to be really into engineering? Yeah, they also crochet. That character who meets the strong man archetype? They have a passion for understanding the language of flowers. That damsel in distress princess? She knows a weird amount about the history of coffee.
I'm just saying. Give your character more weird ass irrelevant traits. It is always correct and very fun.
