Being a caregiver is absolutely noble but unless you're working in a professional environment taking care of the infirm, we don't really give the role much respect.
Fathers (and men, generally) can, of course, be caregivers, but that's only one of a mother's roles. It's far from the only one.
I accept that your "we" is a group of people who don't value motherhood highly. Based on my wife's experiences as a pregnant woman and our experiences being out and about with our children, I don't think that's a common sentiment in the general population.
I'll end with an unsupported assertion and a small mental leap: people are paid for work because it's the only incentive that will make them come to work. Since the 19th century, society has been progressively more successful at incentivizing women to abandon child rearing and home making in favor of commercial enterprise. Perhaps as a result (but certainly correlated), women's sense of well being has been dropping (at least through the latter third of the 20th century). Perhaps this link is causal, and the happiness lost is the reward for child rearing.
This seems to be a huge shift from the previous generation. My father and most of his peers worked long hours and contributed little to childrearing.
I'd guess men don't volunteer to be primary child rearers because stay-at-home jobs have been relatively rare, prior to the past 4 years, men tend overwhelmingly to want to support a spouse than to be supported (which is probably why gay couples have greater household incomes and lower divorce rates than all other categories), and women tend to be hypergamous in mate selection. It's not that there's no incentive to stay home (if you like your children, at least, which I hope is true), it's that there's a strong incentive to go to work.
In my particular situation, tax and childcare would eat most of my wife's income, so she'd be spending 40+ hrs/wk working with other people's children in exchange for less time with hers. She'd rather work with our children and be able to take an afternoon nap.
Would we both prefer to be independently wealthy and not have to work, sure! Might one or both of us work anyway? I probably would. She probably wouldn't.
The remainder of your message appears to be uninformed condescension. My wife is not a chattel slave. Her primary focus is child rearing and home making, but it's not her sole occupation nor solely her responsibility.
There are parts of being single we miss, and parts of being childless we miss. That doesn't change the fact that we've worked very hard for the life we have, find it very rewarding, and wouldn't give it up easily.
Because everywhere I've lived and every community I've been a part of, "we" absolutely do give motherhood profound levels of respect. So much so, that being a mother is an almost sacrosanct role and puts the holder of the title above reproach in many situations.
Also "we" do pay them for it? If you feel better thinking about it that way, their income-earning spouse can be seen as paying them (by having the single income pay for all household spending). Also society at large pays them, by virtue of the myriad subsidies, deductions, services, and programs for children and parents.
The biggest challenge I've witnessed to praising motherhood as a full-time profession, is that mothers who work corporate jobs feel attacked or disparaged if they hear any comment which suggests they are doing any less mothering than the full-time mothers. So we end up in a tricky position culturally, where you can call someone a full-time mother, but a phrase like part-time mother is seen as offensive or inappropriate.
It's very challenging to balance giving respect and recognition to full-time mothers in a way that won't offend mothers who work for companies.
Would be nice.
If men are handing 60-75% of their money over to their wives/partners to spend, I'd assert that those women are getting paid better than men are.
Setting that aside, once you have a family, nobody is going to have much discretionary money and they’ll have even less with just one income earner.
To be honest, I'm not even sure who you expect respect from and why that'd be of terrible importance.