So, buying btc, eth, or any other coin and holding is insane?

Committing to holding anything for 13 weeks without receiving anything in return for that commitment would be insane, yes.

When tens of thousands of minnows start to buy 20usd a week in stake the whales benefit the most,

The main thing preventing minnows from doing that isn't that whales are circle-jerking, it's that 20 USD doesn't buy them any noticeable amount of effectiveness. That's probably the biggest problem for mass adoption on an influx-of-money level.

Why would small investors invest if it all goes to the massive accounts and they have no hope of making roi, themselves?

This isn't happening. My ROI is ridiculous and I spend a lot of time and money I don't have to on community-building.