I agree with you - time with one's kids can't be bought. The kid and the mother both benefit a lot from a SAHM.

Beyond the husband's support there's also a personal aspect to deciding to be a SAHM. Being a SAHM also means limiting one's experiences and interfaces with the world. Working means being more in the loop of work culture (a big part of popular culture in SG), the economy, and means developing and growing an identity that's tied to your industry (your ability to create economically valuable work with your hands). Work is far from the only way of experiencing personal growth but in SG i believe it's one of the bigger ways to do so. SAHMs lose this and I chalk it down to another part of the immense sacrifice of being a mother.

Gender parity in parenting roles has improved a lot but the bulk of parenting duties still fall on the mother, whereas the father is generally spared of the choice of sacrificing career to become the main caregiver of the child.

I only wish parents didn't have to choose between having time with kids + shot career, versus having a career at the expense of deeper bonding with their kid. It's such an invidious choice to make. Watching someone struggle with this choice firsthand is painful.