Indeed. Nobody should limit their investments to just these. For every $1,000 you put into a crowdfunded company, you should be investing at least $4,000 in more traditional and safe investments. And 20% is even a lot. That assumes a young person who has high future earnings potential and a high risk tolerance. 5-10% would be more reasonable for most people.

That said - this is certainly an asset class one could beat the S&P500 with, as long as you aren't just throwing darts and are actually investing in companies you know a lot about and understand.