Worth is a synonym of value. However, the way it's written you use the pronoun "it" without first introducing what "it" refers to. For example, I am very busy and dont have a lot of free time. I have been looking for a woman to share my time with. I've found that spending time with Mary is "worth it". (She's worth my time. She makes me feel that I am spending my time wisely.)

It means: it's a good thing to meet or be with that person because she is somehow ' valuable as a person. It gives you advantages .Apparently, the rest do not. Sorry, it's difficult to explain. Hope it helps