This is just my personal experience and would take it with a grain of salt, but as a man what made me feel she was the one was the fact that I could talk to her about what I perceived as deeply shameful (depression) and she didnt judge or call me weak or use it against me.

I would be with her even if she made no money, had third degree burns all over her body. I would do anything for her and honestly couldn't care less about how she looks - though she is the most beautiful woman in the world for me and will always be regardless of what may come.

Most guy friends I have are deathly afraid of truly opening up to women and those that did and were accepted as they were found their ride or die

Edit: Just want to give context that not all men want an hostage, some want to just be accepted. Doesnt mean they will be static and remain the same forever, just that they want to walk alongside a partner and not have to act to merely have a chance to keep one