Ultimately, decision depends on what you are solving for. If it's purely about $ in the hand, startups never make sense.
If it's about participating in potential massive upside, investing is a perfectly good choice.
Difference between investing vs. joining startup is that you get to build stuff from scratch and operate more like a business owner. You'll do more and learn more in a shorter period of time. This makes a ton of sense IF you like that sort of adventure. Also allows you learn on someone else's dime before you start your own business
If you're joining VC-backed startup, the outcome they'll be shooting for is $1B+ exits, and you can get 2-3% equity if you join early.... so there's that
You can find comparable salary and equity offers here: https://topstartups.io/startup-salary-equity-database/