I don't think you will get many honest answers from regular posters on here @georgiegold but I believe that many older woman (mid-late 50s and older,) who have been married a long time (30+ years) are still with their husband, not because he is made in Heaven, and their love is magic, and the marriage is glorious and wonderful. It's because they know staying with him is easier than leaving. They simply don't want to lose their lifestyle, and many are afraid of being alone.
And it is incredibly difficult for them to leave. I mean, where the hell are they meant to go? Many people struggle to even get a private let property these days, let alone social housing. And even if she did get private let, she would struggle to survive financially. Many women tolerate their husband at best, because quite honestly, trying to leave and be on their own, for many women is nigh on impossible. They can't afford to survive alone. Especially these days.
You always get tales on here of women who left their DH when they were 55, retrained for a new career, found a £75K a year job, made a new bunch of friends, got a lovely new house for themselves, and got a sexy younger man. And how every other man who looks at her and winks, and smiles, and comes onto her, asks her out, and really wants to date her.
The reality for most women is that they would barely be keeping their head above water, they would be working all the hours God sends in a job they hate, and would be quite lonely, and not able to travel or go out much because of only having one wage. And they don't have men chasing after them and asking them out every other day.
Fact is, couples living together will always be better off than singles. It's obvious. Two incomes, but not much more outgoings than one person.
A lot of women 'settled' pre mid 1990s too, and it's a case for many of 'better the devil you know.' Younger women these days have much more opportunities and avenues to go down, and don't have to just settle for any man who has his own teeth, a job, and a car. (Like many young women did some years ago, when women had it drummed into them that it wasn't 'normal' to be unmarried.) As I say, it's incredibly difficult for older women 50+ to leave a marriage of 25-30+ years. Often, tolerating the husband is a better choice than leaving.
Obviously there are exceptions to the rule, and I guess there a few who are very happily married to the most wonderful man in the Universe, but some women did just settle, and would probably leave if they won a few million on the lottery. Basically, if the marriage is just dull and boring, and the husband is just moany and boring, and they rub along together OK most of the time. most women will stay.