Bitcoins have given highest returns in comparison to all the other forms that you mentioned.
All the billionaires/super-rich people have earned money from land, real estates, gold, silver, stocks, businesses

there will be a new history, rich people whose wealth surpasses gold investors, land and the like.
hey, i think the world's most expensive commodity is no longer gold or diamond, it's bitcoin.
and I am very confident, in the future bitcoin will become the most expensive commodity in the world beating all the commodities that exist today.