A major missing piece might be that in the ancestral environment, sexuality and the social sphere were quite different from the modern day. Specifically, (the following points are mere speculation on my part.)
Good dating advice was already an established part of the meme pool, while bad dating advice was a memetic weapon of your competitors.
People knew everyone in the tribe rather well, so a lot of optimization/deception was simply not an option.
It was difficult to hide the fact that you are trying to optimize your sexual life. This effort itself probably signaled against you.
Sexuality and normal social relations were much more intertwined, and monogamy not the norm, so you were better off optimizing your social status and popularity as a whole rather than focusing narrowly on attracting specific people with unsustainable signals.
Radical self-improvement was probably not all that possible in the first place. When your genetics and the meme pool have had time to evolve for your environment, you have little to gain from trying to consciously improve, and a lot to lose.
Religion might also have been a factor in this; If the dating advice was influenced by the tribe’s religion, it is probable that it would optimize for things that are irrelevant or counterproductive.
Aside from these, I think you have not produced much evidence that people are bad at dating. Most of the examples you have provided seem to me to be the kind of things that the public is generally bad at. (Like, the public doesn’t use “evidence-based” books on most any subject.)