A woman who's worried about getting pregnant can monitor her period and take an abortion pill if it's late. A man, on the other hand, can do nothing to avoid the cost of a child besides trying to persuade her. There are women who try to get pregnant against their partner's wishes.
My point is the woman can shut the door and the horse magically teleports back into the stable but the man can't. So men can benefit from being in control of their own fertility.
And that is the reason male birth control most likely will never replace the other variants. Which woman wants to rely on the man taking care of birth control?
One that trusts her partner? What kind of question is this.
I can't imagine my long term partner, now fiancee, wouldn't trust me with something so important to us both. Why even be in a relationship at this point.
one in a stable long-term relationship where she and her partner trust each other to be responsible when it comes to risky or costly actions that impact both of them
(pregnancy is one, sure, but there's also things like blowing half your yearly salary on a sports car on a whim)
And, as we all know, becoming a father when you do not wish to is completely without consequences, making the entire ordeal risk-free. Male birth control pill is useless, QED.