The other being that once women have largescale representation in the workforce, can open bank accounts and credit cards on their own, and can support themselves financially, one of the key pressures to marry is removed. Once there was no fault divorce and women did not need to prove why they needed to divorce, one of the key pressures to stay married is removed.

It could also be the opposite causality. Because people aren't getting into intimate relationships as much (looking out for each other, caring deeply about an individual of the opposite gender), the two groups are naturally diverging into preferring "what's best for ME".

I think the political split between genders is MUCH stronger for singles. It's kind of a trap actually.