The rational comparison is whether you got a good deal relative to the other options open to you, not whether you got a good deal relative to the other people involved in the startup. By the time a startup has raised VC and hired employees, they've usually already passed several risky filters: they've found a market, they've built an initial proof-of-concept themselves, they've convinced investors to give them money, and they convinced you to work for them.

You have the option to swap places with the founders and become a founder yourself. But if you do that, you have to clear the same hurdles the founders did - validate a market, build an initial product, convince people to give you money. And you bear the financial risk that any one of these steps won't work out yourself.

One (productive, IME) way to look at the founder/investor/early-employee/late-employee divide is to think of it as risk apportionment. The founder risks their time & effort for a potentially large payoff if those risks succeed. The investor risks their money on the assumption that the founder can turn it into more money. The employee trades away the financial risk that the venture as a whole might not succeed for reasons outside his control in exchange for ceding most of the rewards if it does. Depending on your risk tolerance and belief in whether the company will succeed, you might choose to occupy different roles in that ecosystem. But understand that what you're being compensated for, when you have an outlandish success that nets a big payoff, is all the ways that payoff could have gone wrong and you might've ended up with nothing.