I can tell you haven’t worked in many startups. The work quality is poor - you are basically firefighting all the time. You’re certainly not building new systems or learning how to scale, etc.

If you work at a startup the trick is you have to take the 5% of your work that’s interesting and try to make it seem like that was the 95%, when in reality the 95% is doing all the grunt work because the company cannot scale staffing to distribute that work evenly or according to specialization.