I worked for one of those 20 year startups. It was awful. Basically there was no drive, no vision. The entire place was a lot of faff and only existed to give bonuses to leadership. All of the interesting and motivated employees moved on long ago leaving only the mediocre types who play political games and favorites. I needed A job and took it when offered, but took the next job as soon as I could get out. I watched many others cycle through, some a lot faster than I did (I was waiting for a specific position to open).