It has been many years, but I had a conversation with a gay acquaintance about this very topic, specifically why he no longer had many female friends. He described his function in his fromer female friend group as "a pet, an accessory, a gal pal with a dick, a shoulder to cry on, an emotional dumping ground."

He was treated well as long as he performed the above roles, and for a while he loved the attention, but eventually he was tired of being the "queer condiment on their meal of life" so he moved on. So did they, by finding another "chicken headed twink" to fill the vacant role.

Granted, this was over a decade ago, so the current social arrangement may have changed, but I doubt it. Also, the gay man in question eventually had an explosive falling out with the social group where I met him, so take his story with a bit of salt.