bitcoin is not money but asset like gold. not worth if use bitcoin for buy a things.
buy bitcoin invest bitcoin why buy money for money if bitcoin is money?
But gold is money as well, maybe people do not use it like that anymore but that is not important gold was used as money for a lot longer than any fiat currency and if people do not adopt bitcoin then it is very likely that gold makes a huge comeback when the fiat system collapses.
Gold is not money, it is an asset and you can convert it to money. Money is FIAT, Gold has value but you can not call it is money. Money can use to payment but we can not use Gold to that. Therefore, you need to know the difference between FIAT and asset.