What’s going on? It’s not that your friends consciously want you to fail, it’s that if you succeed, that means that they have no excuse for not fixing their faults. It’s easy to be fat and say “oh I can’t lose weight” until your best-fat-friend loses a ton and proves you wrong.
Out of self-preservation and laziness, your friends and family don’t want you to succeed too much. They want you to succeed enough to be happy, but not so much that you make them question themselves.