Okay, in my opinion, it wont be happen in anytime soon, although it is a dream of all people who use cryptocurrency right now. There are so many things that make that as my opinion, such as :
1. The price of cryptocurrency is volatile, especially bitcoin. It is hard to make a price product if the price of the currency changing so fast.
2. The transaction fees is high for now.
3. The transaction is not fast right now.
4. Not all people have internet access, or pc, or notebook, or smartphone.
5. Some company forfeited their bitcoin payment system in recent times.
6. Imagine if all the bitcoin is lost because the owner dead or because other reason. it cant be recoverable, and the number of bitcoin is limited.

Now to think of it, I guess the better option is that cryptocurrency as a secondary fiat and the "real" fiat as the main. Everything is based on the "real" fiat like price of a product etc, but cryptocurrency can be used as a payment anywhere.