There is so much generalising about types of people on this thread!
Single mothers all chose feckless men to parent their child(ren). Well guess what? Many men DO change once a woman gets pregnant, it's a well recognised trait discussed often on MN. And men get mid-life crises and run of with an OW. And men even die. Some women are victims of rape or coercive control.
It's all the fault of the Boomers. Who are all loaded, voted Tory, all have massive paid off houses and good pensions or high paid jobs. I'm a Boomer (61). Struggling to pay the interest on my mortgage, can't afford to pay off the capital at present. Earn around £20k, mental health reasons mean I really can't cope with a higher paid job - mental health issues to to being ND which wasn't recognised until very recently as in the 20th century it just wasn't a "thing". I don't vote Tory. I have a tiny pension that kicked in at 60, will only have an even tinier one from current job & state pension at 67. I'm not the only one my age in this situation that I know.
Just move somewhere with cheaper rent/childcare costs. Ah, so give up the job you have, move to an area where there aren't any jobs in your field & massive unemployment. Rents and childcare are higher in some areas for good reason - because that's where the jobs are!
Childcare costs are too high & a rip off. Ever done the full maths of running a childcare business? Employing staff costs over double the wages you pay them. Premises rental. Insurance. Premises running costs. Legally required documentation. Legally required staffing levels, and having to have either "spare" staff or pay for agency staff when there's sickness. Consumables. I know of at least 3 childcare places that have gone under in the last year due to losing money.
I'm single with no dependents, have a mortgage and a very small pension income. Due to this I can't claim a single benefit. I have an ND disability which has restricted my ability to get & keep jobs, but doesn't fit the criteria for any kind of allowance. In spite of this, I am totally supportive of the OP and single mothers in a similar situation being able to claim UC.
I think the big takeaway for me from this thread is that not only is everybody different, but there seems to be a total lack of understanding by many people that this is the case and what works/worked for them won't work for others