@zorrow For me, one of the main factors in feeling content with life is being solvent. No mortgage, DD (mid 20s) left some years ago, so no kids to provide for, plenty of savings and surplus income, and low outgoings/no debt.
I also have a happy marriage - most of the time - a great relationship with DD, several good friends, reasonable health, (a couple of health issues that are managed well but am overall OK,) I live in a lovely village/rural environment, I have an easy part time job, and a DH who earns quite well, and as I we are said solvent/quite well off.
All of the above (friends/decent marriage/close/family/reasonable health etc,) are essential for happiness IMO and IME, but if you are financially poor, life is very hard.
Money doesn't necessarily equal happiness, but the lack of it causes misery.
We have had periods in the past (me and DH) where we have been brassick and struggled badly, and been in quite a bit of debt, and we were much more stressed and miserable then. I think most people would agree that life is easier/better/less stressful if you're solvent.