I would agree that in an ideal equal world, men and women would pay half for dates.
However, we live in a world where men and women are in very different situations, and thus, treating men and women the exact same in all situations does not necessarily lead to equality, but rather can increase inequality in some instances. Equality does not necessarily mean same. For instance, 2+3 and 4+1 are equal, but not the same.
In this current society, women paying half for dates would only exacerbate inequality. On average, women make less money than men, and also are required to pay many more expenses than men, from menstrual products to bras to clothing (it is considered unacceptable for women, but not men, to rewear clothes) to gyno appointments to makeup. There is also evidence that women’s products cost more than equivalent men’s products (aka the pink tax).
In our current society, men paying for dates serves to decrease this inequality in expenses required to be paid. This is why I am not concerned with the societal expectation in which men are expected to pay for (hetero) dates, and in fact am opposed to this expectation being alleviated (at least in cases where the man is financially capable of paying), until we acquire the ideal world in which men and women make an equal amount of money and men and women are required to pay an equal amount of expenses outside of dating.
In this current society, expecting women to pay the same amount for dates will only serve to increase inequality.