First, not all startups will produce venture style returns (say 7x in 7 years), for the sub-priming of innovation arbitrage has created a dense fog of false positives of innovation, resembling at most downstream sub-optimizations from an existing normalization of truth, often laced in advertising schemes detrimental to the integrity of society. The very reason why most startups turn into small or fake businesses unable to make a lasting and meaningful impact on society.
In the case of a venture style startup (a formula-1 race in a world full of cars), it is essential to understand how and what role you play in the multi-stage rocket that sends such a startup to the stars. Since most individual investors are unable or unwilling to cough up $25M or so to make a dent, they are implicitly subjugated to the collusion of groupthink to have the propensity of viable returns. The kind of groupthink that systematically ignores outliers.
Hence, the key for you is to assess whether you as an investor have the foresight and wherewithal to dare and be able to make a real impact on society, and have found the startup to which that profile matches. Otherwise, you are what we would call in the business of venture capital, a play-investor, dabbling in private stock trading along a chain of greater-fool investors in the hopes of landing someday somehow a diamond in the rough.