What many men fail to realize until much later in life, if at all, is that things like kindness and decency have little to nothing to do with how much a woman is attracted to you. A lot of this delusion has to do with bad/naive parenting, and to an extent society instills this message in boys through cultural programming from a young age.

What women value first and foremost is their attraction to you, whether that be due to looks, personality, talent, etc. Then comes other things like financial status, social life, and so on. Kindness does not factor in here for the vast majority of modern women, and if it does it's a very small factor compared to everything else.

This might seem obvious, but I see too many men who are concerned with being a decent man when it comes to dating, and it needs to be emphasized that it doesn't matter. It's only important in the sense that you shouldn't do anything drastically immoral that could hurt your prospects, but outside of that kindness is not something that a man should be concerned about in dating.

What men should really be focusing on is increasing their attractiveness and taking advantage of power dynamics (wealth, age gap, etc.) in order to find success- this will work much better than being the nice guy. That's not to say you should stop being a kind person if that's what you genuinely are, it's just that it's something that valued by women when it comes to attraction and if you want to have success you should stop emphasizing it.