I have recently taken a career break to look after my 3 kids. Luckily, my career was lucrative so I have a good investment pot of my own, though I see it as all part of the same family pool. I was the default parent, so my career had to suffer for maternity leaves, pick ups and sick days etc, so I earned less than if I had been able to put my foot down but did well.
My husband's life and career has improved already for me taking a "break", in fact he has recently increased his earning potential significantly and might have struggled without the support to travel etc - I worked up to my third pregnancy so he really does understand what it is like to be a good partner in a two demanding jobs household and appreciates the cushion he has.
There are lots of joint decisions we have taken that are better or worse for quality of life and finances and it is hard to totally pick them apart and say that one person has freeloaded off the other financially - I could have worked more remotely than him and lived in a cheaper area for housing, childcare etc if not for his job. Sure, our combined wealth is greater as a result, but I could have lived in an area of the country where I could have had my lifestyle on just my income if it had just been me. If we did split up, the assumption would be that we would live close by in the same area to avoid uprooting the children and so that might require some form of transfer of wealth from him to me to be able to enable that now his earning potential is higher. Obviously, if our kids were grown, that might not be such a consideration, but it wouldn't necessarily be unreasonable to expect for both of us to be able to stay where our friends/family are and have a big enough place for our kids to stay. I don't feel in any way insecure about my contribution to the joint pool - I've done the vast majority of night wakes for my kids, for example. How to value financial or non financial contributions?