Actually, Hithere, I do think a spouse working full time makes a great difference. When we had FiL here and dh was working long hours in a demanding job, it meant I had FiL from at least 8 in the morning until 7 at night, non stop.
The pacing, the endless repetition of the same question, the demanding to go out on his own when I knew he’d only get lost or run over, the refusal to wash or change his clothes, the truly frightening rages now and then when he was frustrated about something over which I had no control.
The endless, endless patience I had to exert, all day, every day.
Plus I was trying to work from home. And he was often up and down half the night, banging and shouting and demanding to go out at 3 am.
It was relentlessly, utterly exhausting.
And I had always been very fond of my FiL.
In the end a care home - and it was a brilliant one - was the only way.