The company I work for now is 5 former QC engineers. Different markets, different projects than what they did at QC. But they did it as a side-hustle for 1-2 years before taking the leap.
Been a long haul but I bet they have enough equity remaining among them each to 5-10x a 40 year QC career when they exit. And they’ll do it in 25% of that timeframe. Not for the faint of heart and high probability of failure, but when it works, it’s impressive. And in most cases, that job is still there if it fails.