I am the person described in the requirement list. I brought 2 startups from seed to series A, built a cashflow business of my own, led teams, have 5+ years of runway (yes, in San Francisco), and actively looking for a potential idea + business person. I have worked my ass off for the past 10 years to put myself into this position. I'm doing startups to fulfill the intersection of broad positive externalities + financial reward space, which is possible, and I did it 3 times already. I'm looking for a cofounder+idea because what I can do alone is limited. Over the past 2 years, I have reviewed >1500 pitches, talked with 150+ founders, had in-depth conversation with 10, executed (and failed) with 2.

My counterparties are not real.

In descending order of frequency:

* Tirekickers / wannabes: these people have fantasies about doing a startup... someday, but definitely not just now.

* Super excited about <thing/area>... has no related experience, fails at basic business ontology ("target market", "valueproposition") <- 95% mark

* Has no hypothesis about marketing channels, nor any insight on why this particular combination might work

* fails on all of market scoping, TAM, customer development, financial model <- 99% mark

Rest: limited operational experience, OR self-defeating / low psychological resilience, going nowhere.

There is a laundry list on sibling comment (https://news.ycombinator.com/item?id=39904704) for ticking boxes. My current hypo, is that peeps who check these boxes AND don't have a tech cofounder on their rolodex typically go to angels/VCs, and get a recommendation from them; and therefore will never appear on any markets for cofounders. Curious if this matches your experience.