Extracurricular being meaningful

I was reading something on the Georgia tech website and they had said that “most students we find are only involved in 2-3 ecs in a meaningful way”. My question is what’s the best way to show or portray your ecs as being meaningful. The common app barely lets you write anything. Appreciate some insight into this matter!

Leadership positions, specific accomplishments, hours spent on EC etc.

Demonstrating a genuine interest in the EC- for example, rising to a leadership position in a few clubs & not just having 12 clubs that you don’t really do anything for.

Is writing about your ECs in essays (perhaps the common app) a good thing since it provides additional insight?

Use the essay to tell the admissions officers something important about you that cannot be found elsewhere on your application. If that happens to be how you have been dramatically impacted by working on a particular EC that is fine. but it is not at all necessary.