Our world is set-up for a default male biology. Women do not fit that pattern and a feminist ideal is to make changes so that 'man' and 'male' are not the default. This does not just apply to how we shape our career paths and work places, it applies to biology as well, so that male bodies, and how they work are the default for medical intervention, which causes problems for women, who do not exhibit the same symptoms for some diseases (e.g. heart diseas and strokes) and whose bodies do not react in the same way to medicines because their chemistry is different. In the work place, everything is geared to how men's bodies work, menstruation, pregnancy, breast feeding and all the messy reality of being a woman, like needing to pee much more often, must fit to a male pattern. This is what I mean by 'male career path': train, qualify, work, get promotion, retire. A woman's path is more like: train, marry/find a partner, have children, rear them either full-time or part-time and run a household and its budget, lose promotion at work as on maternity leave, does not return etc, return to work at lower leverl than she began, progress less well, retire (now at same age as men), have a smaller pension. Some women will choose to work and not have children, or have full-time childcare (which eats up most of their income), some will do as you suggest, and share parental leave. Lesbian couples have the same problems as a heterosexual couple - someone has to bear and rear the children, do the cooking etc (sexual orientation makes no difference to this pattern, and it will apply to gay couples as well, where one must put their career on hold to look after the children, and probably give up some promotion - the only difference is that a gay couple will not have the biological imperatives of women).
You say: 'A world in which certain paths lock women out because they’re only for men isn’t one I’d want to live in' - that world is the one you live in, where women are locked out of careers, jobs, work in general because of their biology and because they bear the burden of reproduction. I want to stop locking women out, and to do that women need to be able to choose to stay at home if that suits them and their family without it wrecking their careers and pensions.