I read an autobiography of an American Carmelite nun. One day a woman came to their cloistered convent & berated them for not getting out into the world & doing good missionary work, like St, Therese, Little Flower.
Of course St, Therese WAS a cloistered Carmelite nun & only lived a short life of 24 years, but one of her apostolates was to pray for the missionaries, and she corresponded with some. She is considered a patron saint of missionaries.
As for contemplation & meditation, which we all can do, but may seems like a waste of time & selfish or self-centered, I tell this: In airplanes they tell us to put the oxygen mask on ourselves first, then assist others.