I see what you mean and do understand it . At the current LEO and other Steem Tokens are very risky because of their volatility and so also carry a high degree of risk . Traditional investments are quite opposite - well made , well designed and relatively smooth. Value of a token is only a perception the same way the value of anything in life . Likewise if you are good with traditional investments then you have a lot of additional perks that are not limited to easy of use ,diversity and ease with regards to legal matters.
As you had stated the returns from these miners will drop with time as the difficulty increases which has already been seen on the current BTC and other cryptocurrency mining charts. Also fellow investor I would say the degree of risk is not IN the investment but rather the INVESTOR. Trading has proved this point many times (also Real Estate is another one that presents this fact as true).