Pros
A great place to start your career if you're young, like 20s-early 30s. If/when you want a life (partner, balance), it might be time to move on. The expectation is to hustle and grind and the compensation does not match. There's no HR. Things that should not happen happen. Like different treatments/allowances for different employees, information not being shared with everyone, and other things but I won't go into details. Founders have good intentions but some of their requests are ??? You will learn a lot through the work if you're early in your career, but eventually it's not worth the toll it takes and sacrifices you have to make. Most employees leave after a couple of years. When you work somewhere else and get a different experience you realize that it's sort of a crazy place, but it is a startup after all. The 2 or 3 people who have been there for a few years longer have a high tolerance. From what I know, they don't get paid well either.
Kontras
answers shared above ^ ^