It's more than just gifts. Transfers of money from men to women include:

Taxes - Men pay more tax because they earn more, but governments spend more money on women than on men

Household spending - Women are responsible for 85% of consumer spending. A man may bring in the majority of money to a household, but typically the woman decides how it is to be spent.

Divorce - Men's assets are likely to be given to women rather than the other way around.

Child support - Typically women receive money from fathers for eighteen years.

Alimony - Men are forced to pay women large sums in perpetuity after divorce.

Inheritance - Women typically marry older men. Men are likely to have a shorter lifespan than women. Thus, husbands usually die before their wives do, and the wives inherit the assets.

There are other means of transfer too, but these are the main ones. The reason it doesn't get talked about is because it would undermine the wage gap narrative.

I wonder if the Internet could get around this problem by creating an anonymous, crowd-sourced study with peer review? Wikipedia is one example of how such a thing could work.

Credits to r/mensrights