Everyone in silicon valley is familiar with founders that got seed money or connections from friends and family. My point is that even having a safe place to sleep isn't assured for some people, and folks should remember that when they pat themselves on the back for 'taking risks' founding a startup. Some people would be taking much larger risks than others.
I think the implication is that, as opposed to starting a romantic relationship with someone who can support you or a side hustle or etc., having a supportive family is much more passive (and somewhat a roll of the dice, but generally speaking if you were lucky/privileged enough to be born into a family who can emotionally and/or financially support you, there probably isn't much labor/effort you had to put into to make it that way).
It's for sure a huge benefit; I think their point is that it's a huge benefit that doesn't require effort (just chance, or maintenance of good communication/relationship).
Even something as simple as a supportive family is a huge leg up compared to those who don't have it.