'significant equity'. Who outside the founders and maybe five first employees really have that in a startup? If owning 0.1% which gets diluted to 0.01% before the startup sells for say 40MM bucks four years later is significant to you...
It depends on what you mean by "startup" I suppose. I've worked for three and in each I've been one of the first dozen or so employees. You don't have to be a founder but I think that being a core "early employee" with a fair equity stake is the right way to get the real "startup experience". Anything else is like.. well working for an established company, and doesn't have the same vibe, or excitement.