What makes a man marriage material & what makes a man just casual sex material.

I was told I am a very handsome man by my peers in university and at work. When I go out I'd get both women & men flirt with me. I am 6ft have large frame and I'm an amature wrestler. Whenever I ask out ladies they always accept but when they eventually find out my intention is just gf/bf or friends with benefits and not to get married (as I can't afford it) they leave me they always say "I need more than sex from a man".

Aren't people supposed to have sex or something before getting married.