There are always numerous exceptions (that prove the rule), but the reality is that people that achieve greatness in solitude can only do so because they are in a context that permits it, i.e., civilized society which requires strong families to exist. For the vast majority of people seeking greatness they are doing so so that they can benefit society to enrich themselves and their progeny and many, many of those people are doing so to attract and keep partners to have children. It’s a basic biological fact that most motivations toward valuable output are in service to the next generation.
Discussion
This is why I say that it's where to start from, and not a goal.
Oroboruos
Not when it's described as a "means to that end".
It's not an "end".
I'm sure that it's easy to think of a healthy family as some "high goal", because so many families (in the modern western world) are not healthy. That doesn't mean having a healthy family is the zenith. It's the base.
I’m ok with that metaphor.
its also absolutely true that the vast majority of people are more likely to find personal satisfaction in being a good parent and spouse,
regardless of any social benefit or other valuable output.
otoh, there are plenty of people who raised their families and DIDN'T find that contentment, eventually seeking elsewhere.
so
YMMV