Well, here in SV, everyone kinda knows what other companies pay. You just didn't have friends in SV to tell you before the interview how much that company pays.
In general, there are top-tier companies, FAANG + Uber + Lyft + AirBnB, that pay X. Then there are lower-tier companies and startups that pay roughly X / 2. So, you're unlikely to get FAANG total comp at a no-name startup.
You have crafted a strange model. What are the upsides to such a system, to you, the employee?
You get to learn first-hand why being a non-founder at a startup is almost always a bad deal in terms of compensation.