That's my point. The social convention persists

because it allocates forms of rejection. You don't feel rejected by women who don't ask you out, because the "man asks" convention is protecting you. Neither are you aware of not being challenged by the woman who says "Ok, but only if you pay," because the "man pays" convention protects you from that form of rejection. The fact that you aren't thinking about rejection doesn't mean that you would like living in a world where you had to deal with more of it, or that women would have to risk rejection by demanding the man pay. Think about the problem as an engineer...