They say if you just leave your money idle at home, nothing will happen to it; it won't generate a profit. Our fiat money is just held in our homes but isn't producing a profit for the future. In short, our money is just sleeping.
Unlike holding it and putting it into Bitcoin, it's sure to have a profit in the future, depending on how many years you do it to get a profit. It's the same thing we do with fiat, but Bitcoin is volatile, and that's the reason why it's good for long-term investment.
It doesn't even matter how long you hold it, as long as you sell it on the bull period, you should be making a profit, and earn mroe than the inflation. Wheras keeping it at home, in fiat, will make you lose it all. Even keeping it at bank, in some savings account, will make it gone too. So, there is no situation where holding fiat will get you richer.
Even if you have more fiat this year than last year thanks to interest, the interest is usually a lot lesser than the inflation number, which means, even though the number looks higher, the value of it is lower. So that is why we need to make sure that we are not selling this badly right away. If we can do better, then we can definitely make some good money out of this and do better with crypto instead.
Allowing you in holding Fiat or saving it in the bank is one of the tricks the government will use to devalue the worth of your financial powers, because they will either increase the interest rate and create inflation and at the end of the day, that fiat your savings in your bank account will gradually loose it worth, this way the government is using a proxy means to reduce your purchasing power and controlling your financial lifestyle. Crypto especially Bitcoin doesn't allow for those shenanigans the government always brings up in reducing out financial liberty, which is why we should do more in tilting towards more Bitcoin possession.