At a certain age, female friends can be quite rewarding in getting invited to group gatherings and expanding social networks. This is a mutual interest being a young person living in a big city. You want to know more people whether they be guys to hang out with, other women to date and generally young professionals in professions clustered in cities.I find having women as friend always an uneven expenditure of value. It's very rare that it's beneficial to me as they are not really interesting since our interests are no where near close. Usually it listening to their problems and rambling on about their lives. As for the coffee date it will be entertainment and get me out or something to put my penis in.
The key here is don't get into lopsided relationships with attractive women where you take them to paid events, always lassoed into helping them with things, etc. and get nothing back in return. These women are used to having everyone kiss their pretty hineys since puberty. At the very least, if you take them to an event where colleagues or friends are present they should look great and have polish.
Anecdote alert: I even had a pretty friend ask me do you want me to wear something that tastefully shows off my legs. She deliberately spoke with the head of the company and got us invited to sit next to him and his wife at his table. They loved her. She knew she could be helpful.