> I hope we can relieve women of the pressure of motherhood this way.
You should ask the mothers you know how they feel about that? The majority (i'd say the vast majority), consider motherhood the most important and best thing in their lives.
Plus, the only alternative is men? Who by definition cannot be "mothers". So you're describing being raise only by fathers. So.. now the suggestion is just adding pressure of fatherhood? lol
> Maybe we can even develop more equitable societies where any gender can raise any children, or all genders will be expected to raise all children.
All genders, in all cultures, do raise all children. That said, each likely plays a different role. Just imagine some hunter gatherer culture - men provide meat, teach their sons to hunt & fish too, teach their daughters to pick honorable men for husbands, maybe even find honorable men. Women, teach their children to clean animals, make clothes, make food & fires, etc. This tradition has largely stayed the same.
In the first world, Women have changed their roles, as automation replaced the need for many of the tasks. Men have continued to provide a similar role. In both cases, I argue parents are increasingly teaching their children less directly; outsourcing it to "educators". That said, I think it's had detrimental effects on families and you can see that in the depression rates, competency rates, divorce rates, etc.