If you’re going to do that, why not just co-found something? Your position will likely be higher percentage than the amount of de-risking that’s happened in the company you’ll join. “First [non-founder] employee” is a very poor position to take on from an expected-value perspective.
The derisking value is greater than you estimate, imo. Getting from zero to that stage is very difficult for even the most capable and experienced people.
(Also you save several years of getting the company to that stage, which means you'll get many more rolls of the dice for the same number of years)
Way higher risk and totally different "day to day". You have to really want it, have a good idea and good team lined up, and be ready to sacrifice a lot.
