Is it really the best way to invest your money?
Because of the way Bitcoin generates value or becomes more expensive, it could potentially lose all its value and became worthless.
Who assures you that this will not happen?
Government issues paper money by putting gold as a reserve in most cases but these days the printer is just printing the money without any mechanism causing extreme inflation. May I ask you who will assure that this excess printing of fiat money should not happen?
This shows that even the assurances by the government are useless and fake. So better do not look for assurances but look at the bitcoin model. There is no flaw in the bitcoin model and it's hard to believe its demand could go down when there is too much inflation on the alternative currency (fiat money).