Bitcoin,fiat and gold have their own purpose why they exist. Bitcoin is definitely the best in terms of investment because of the higher earning potential. And it is good to invest both for short and long term if there is really knowledge about crypto or digital currency. Gold is for long-term investment that has been around since then. Fiat is what we use every day, with or without bitcoin, the truth is that we need fiat for our daily life even if we want to invest both in the stock or crypto market. Those three act as a medium of exchange which means they are all important.