I think his point is that if the existing service has a free plan then it is going to be hard to undercut them on price. Dropbox and Robinhood want to dominate

I think his point is that if the existing service has a free plan then it is going to be hard to undercut them on price. Dropbox and Robinhood want to dominate the market. OP's advice is for making a couple hundred bucks a month on the side.