If you lived in the UK you'd probably come across a lot more single women, as it's quite common for people to be single here. It seems to be the norm for couples to split up and they don't always meet someone else straight away. I know people who have gotten married only to split up less than a year later. I blame the internet, as people are often advised to just leave their partner whenever the slightest problem arises in their relationship. Unless the relationship is false or abusive, most problems can be addressed and worked out together, but most people these days just walk out of the relationship instead, even if they have children. Some couples split up when a loved one dies, and I never understand that, because I thought that you'd want your partner more than ever for support (unless the relationship is abusive but I'm not talking about that, I'm talking about genuine relationships).
I've been through a lot with my husband but we stuck together through it. In the 9 years we have been together we lost both our mums, and he's been fired from his job a few years ago, and the pandemic was stressful, and he's had his moments with getting too drunk, which caused me massive anxiety as I'm not very good at dealing with drunk people and I see it as irresponsible behaviour.
But despite all that, we've never lost any feelings for each other, we have stuck together like couples should, and worked through our problems. Even non-abusive relationships come with problems, especially if one or both of you have baggage, like my husband has (kid problems).
The only thing about being in a relationship is that I can't buy toys. Well, I can, but it would be quite a bad choice, given so we live in a small apartment and don't have much money, so buying toys would just be wasting money and taking up space, and it's his apartment as much as it is mine, so you do sometimes have to compromise. But the internet would probably be like "if you want to buy toys then go for it, if he doesn't like it then he's not a good guy to be with, leave him!" Very, very poor advice and is not a valid enough reason to divorce and leave a man you love. And the internet would be telling him "she left you because she thought toys were more important than you? What a cow, she's not worth your time!"
So that is why there are so many couples split up. Although I'm afraid I can't explain why UK people seem to listen to shoddy, contradicting advice on the internet more than people in the US.