For those living as couples who say it's hard financially, why don't you take in a lodger to make life easier?
What, your DC wouldn't have their own room? Well, according to some on here, that's not a problem if you're a single person with DC. You're making a choice to have a place with room for your kids.
Expecting to have a place with a bedroom for yourself and at least another for your DC is not an unreasonable expectation, whether partnered up or single.
It's not a race to the bottom and just because one set of people find things tricky, doesn't mean they shouldn't get help just because a different group of people find things tricky for different reasons.
Living on your own is more expensive. Fact. Some of the solutions given by people on here would not save any money. My eldest pays more than double in rent for his room in a shared house at university in comparison to my mortgage, partly due to location, partly due to the fact I bought a house that needed a lot of with and have spent time renovating it (myself).
I'm in my late 40s. I left an abusive marriage with next to nothing, despite being the one who carried most of the financial brunt during that marriage. I can't save to top up my pension, which is woefully inadequate as I've had to start again from scratch.
As I said in an earlier post, I'm lucky in comparison to many, but being able to afford housing with sufficient space to give DC a (shared) room should be a basic minimum expectation in mid/later life, not a luxury.