> there goes their livelihood until they line up another job.
This risk exists with any employment arrangement. So arguably the risk is merely the greater likelihood of the startup failing vs big corp laying you off.
For employees, there is employment risk, reduced compensation, potential increased difficulty of finding next job. For founders there is the first two but generally finding next job is easier (because you get lots of managing/etc experience potentially faster than you would normally).
This risk exists with any employment arrangement. So arguably the risk is merely the greater likelihood of the startup failing vs big corp laying you off.