Bitcoin has been used to buy and sell goods since the past, look at the country of El Salvador. The country of El Salvador is using Bitcoin as its currency, and all buying and selling transactions are done through Bitcoin. You can never imagine the rate at which Bitcoin is spreading all over the world these days. Because in countries where Bitcoin is illegal they use it secretly, but I think Bitcoin is used all over the world either openly or secretly.
Well, you are right about people using Bitcoin secretly or not very openly in countries where Bitcoin is either illegal or has no law at all. In my country, we don't have any law regarding cryptocurrencies in general, but the banking sector doesn't allow transactions related to cryptocurrencies, and the government has given signals a couple of times about cryptocurrencies being bad or related to criminal activities, etc.
We do use Bitcoin and other cryptocurrencies but since financial institutions are against them and can block our accounts or confiscate our funds, we try our best to not let them know that any of our transactions are related to cryptocurrencies or we can get in trouble for it. Hopefully, we will see this getting better over time.