You can spend them in so many project. Which are related to bitcoin. You can also invest them in your business. You can spend them to open a online market. You can spend them to buy your accessories.
There is no denying that bitcoin will be a great and profitable investment if you have enough knowledge and acquire the skills specialised in this field. And it is also a brilliant alternative to fiat money when it comes to online shopping. Bitcoin has made international transaction a lot easier and faster than before. But using it directly in reality in my country is not a dream comes true but rather a fantasy. My government doesn't like bitcoin and what it could do so although bitcoin has not been banned, there is a fat chance of it being accepted as a currency. So it is really hard to find a bitcoin ATM or any shops or restaurants that use bitcoin. I have seen some coffee shops using bitcoin but most of them didn't last for long. So I can only buy fiat money with bitcoin and use them instead.