Zillow tells me average house price in Palo Alto is $2.6m, average rent $5k. Do you own/share a house? I'm in Europe, so basing myself on public stats.
Thanks for answering! So the data is not far off. I should add "or is single and has no children" to my comment. Nothing bad about that, on the contrary, it does mean older founders with family or other obligations will need to bring/sacrifice their own nest egg.
I think a total household income of ~150-200k is right around the cutoff for 4 people to live in Palo Alto together. You can split that up however you want though. In my case, that's 4 people earning ~50k rooming together. In the case of a family, one person earning 120k and the other doing a startup earning 50k (plus 2 non working kids) works too.
You're right that someone trying to support a family on a single income at 50k would have a tough time, but I think the range of people who can make it work is a lot broader than you're making it seem.
To be fair two non working kids have a lot more costs than a frugal 20 something. Childcare alone in the bay area is probably in the 10s of thousands a year range.