On the other hand if you want to work at a startup because of the lifestyle or mission then don’t expect to make any (well not much) money if the company succeeds. The sooner everyone wakes up to this reality the better.
Most people are not rich, even software developers. Only the rich can be angel investors, because it's illegal to issue securities to non-accredited investors. Being an accredited investor requires a net worth of $1M excluding your house, or a steady job with $200K/year pay ($300K if married), and 2 years at that pay level before you can start investing. There's no net worth or income requirement to work at a startup and get equity that way.
Joining a second rate start up is even a worse idea than working for an established company - you will end up with less pay and worthless options.
Edit. Wow this comment hit a nerve with some people here.
I was more making the point that it is not wise to turn down a good salary with an established company for the tiny level of equity that you will end up with at a startup and if the startup is not perceived by the investor community as being the next unicorn then this equity will be worthless.
Devs in the 20-40 employee number were probably making out with $4-5Million
Of course things were less institutionalized and procedural than they are now.
Now I think the balance has swayed in favor of the founders/investors much more than it used to be but thats just anecdotal