I'm in that position right now, and have done it a few times in the past (my entire career is switching between startups and public companies).
I work for startups because I get a ton of responsibility for things I would never get at a big company. I get a chance to learn a ton of new stuff.
Through my career, I've made all my money at the public companies, and had most of my skill growth from the startups (Netflix being the big exception, where I both made money and leveled up my skills).
I did not get any stock in reddit when I worked there. I worked there between when they were first acquired and when they were spun back out. The guys I hired got f-u money and I couldn't be happier for them, they deserve it for how hard they worked and how long they waited!
I work for startups because I get a ton of responsibility for things I would never get at a big company. I get a chance to learn a ton of new stuff.
Through my career, I've made all my money at the public companies, and had most of my skill growth from the startups (Netflix being the big exception, where I both made money and leveled up my skills).