I'm not sure about all of that, but a couple of relevant points come to mind: men who'd lost their wives tended to die sooner after them, than women who'd lost their husbands source, also men are something like 6 times more likely to leave a sick wife than women are a sick husband (source.
So while I'm sure there's more nuance to it, the general trend seems to all point the same way - men need women a lot more than women need men, they require more care but are also quicker to discard their partner when they can no longer provide that care.