I feel like my partner is only poly because he’s too addicted to sex and making bad choices to be monogamous. I don’t think it’s about feeling connections with multiple people. I think it’s strictly for the benefit of being able to have sex with whoever whenever. He keeps having sex with people he says he won’t and I just keep asking ‘for what?’ but there’s no real answer and I’m sick of it honestly. He won’t stop and he doesn’t care who he hurts.
If you are “sick of it,” and feel that your partner “doesn’t care” if he hurts you, leave the relationship. If you feel that he is not being honest with you or himself about why he is making certain choices; if you feel that he is being irresponsible; if his actions are causing you pain or frustration - leave the relationship. It doesn’t really matter whether you’re right about his inner thoughts or motives, what matters is that he’s behaving in a way that makes this relationship no longer happy or healthy for you.
(Things I feel obligated to say: you’re not psychic or able to say why exactly someone does something, and it’s rarely appropriate to question or invalidate someone’s stated identity, even if you think their motivations are suspect. Only professionals are qualified to diagnose your partner with an addiction. Also, it’s perfectly fine for someone to pursue non-monogamy so that they can have lots of sex; that is not an inherently bad reason to be polyamorous.)