OP, I would greatly advised that you don't think of your situation as it is presenting now but also the future. It is so easy to make choices that make your life easier and more enjoyable at the present time and ignoring the future.
The future will come much quicker than you think though. Working is not just about bringing as much money right now so you can get nice cars, entertainement, holidays etc..., it's also about an investment to a better life in the future. If you work FT on a low income, you have a much much better chance to see yourself in a much better paying role in 10 or 20 years time, of course assuming you show dedication to your job and constantly look at opportunities to get promotions, internally and externally.
The way you are considering your life, you are maximising your current income, but each year your OH is working minimum hours and you are not working, you are loosing quite a few thousands of opportunity income for your future.
I became a single mum of two toddlers in the early 2000s. It was quite a good time to be a mum on benefits then when you owned your hours, interests for the house paid, and no need to look for a job until the youngest was 12, and tax credits that were quite generous. A number of single friends I became friends with opted for this option and yes, it was tempting at times when I spent so little time with my kids and I was always stressed and exhausted, but I didn't.
It's now 18 years later and I am so grateful. I have a very good job, that pays very well. I moved up 4 salary bands since then. I have been able to offer many things that have helped my kids, activities, driving lessons, travelling to visits uni so they could make the right choice for them etc...
I am now in a comfortable situation, a nice house, nice cars, lovely holidays, can treat myself to more or less what I want, and support my kids through Uni. I have a good pension so I know I will be ok after retirement. I have no financial worries.
My friends who opted to be single mums are now the ones wishing they'd made different choices. The minute their kids left home, went tax credits and maintenance and they found themselves with very little income. They have had to go from not working, to working pt, to working FT and the adjustments have been very tough on them. They find working FT much harder than me because I don't know any different. Their lifestyle has taken a deep dive and they are having to budget for everything. Worse, they have nothing to hold on to to make the future brighter except for trying to meet a good man with a good income.
This is the safest aspect of this opting to live on benefits lifestyle. Families are only able to afford a decent life on them because of their kids. The moment the kids go and everything goes with it. It is such a risky choice of life, after all, there will likely be more years to come without kids than there are with them.