Volume after volume has been written about the benefit and virtue of religious life, and I know what little I can write here will not do justice to it, but I’ll consider a few aspects of it that may interest you.
First of all, religion has always been considered the most objectively perfect state of life, by its very design and its radical living of the evangelical counsels that most closely conformed to Christ. Thus, we do best considering it as what it is, rather than by what it does. Our mindsets today have this unfortunate way of looking at everything through a utilitarian or functionalistic glass, which does great injustice to a good many things. This is not to say that religious don’t do many things that are useful or necessary, but this is all subordinate to their primary purpose, which is becoming a living holocaust to God.
To give something of an idea, a missionary bishop once said that he would sooner ten contemplative religious praying for his missions than a hundred priests actively evangelizing. It was once revealed to St. Teresa of Avila that one of her prayers caused the conversion of thousands of souls. As has already been mentioned here, we’ll likely have no idea of their impact upon the world until the next world–that world which they are already starting to live here.
Some reading of some of the work written about the religious life might give you a broader perspective, as might some of the lives of those great many saints who were religious. As a particular patron in this mind, consider St. Gertrude of Nivelles, virgin and abbess of the Benedictine monastery of Nivelles near Brussels.