Well.... there is an argument that parents (which includes women) haven't successfully been raising all their sons for a long time - because we have both entrenched patriarchy and a high suicide rate in young men.

Theoretically speaking, if single mothers become normalised and economically supported and there's less stigma attached to this set up because of feminism, we'd expect to see a gradual reduction in toxic-masculine behaviours. That doesn't seem to be happening - though I am prepared to concede it might.

Some single fathers handle things better than some single mothers, I would think the reverse is true in most cases but I know of a number of children raised by their fathers who were exceptionally well-adjusted. In the two cases that spring to mind, the mother died when the children (a boy and a girl) were both young and he never dated again. In the second case, (a girl and a boy) the mother abandoned the family to have an affair and the children never forgave her for this - though they might now, as all these people are adults.

What I suspect is best is that children are exposed to figures of both sexes and those figures are able to both co-exist in harmony, and highlight the strengths of each other, whilst also filling the gaps left in parenting by the other without society turning into a war around them.

Here in the UK we have Children and Family Court Advisory and Support Service (CAFCASS) who will talk to children about where they want to live in court proceedings and set up a CAO (child arrangement order), a child cannot legally make such a decision until 16. Many cases do not get to court, parents simply separate and children must allow their parents to sort it out between themselves. This generally favours the mother in most instances - though favour is perhaps the wrong word.