This has been the fundamental problem with all cryptocurrencies.
The point of a currency at its basic level is to facilitate exchange of goods and services. The principle being that: I will accept an amount of currency for giving you something, on the assumption that I will be able to exchange that amount of currency for something else of equivalent value (whatever that means) at any time in the future. Just to emphasise that last bit - AT ANY TIME IN THE FUTURE.
That last bit is important if we want to save our currency in, say, a bank account, for long periods.
Therefore one of the critical success factors for a currency is that its value is stable. That its value today will be roughly the same as its value in the future.
Where a currency's value is as volatile as Bitcoin or any of the other ones, then they are as useless as Zimbabwean dollars.
So why is anyone buying them at all ? The only reason people are buying them is because they think there will be capital growth - ie they can sell them in the future for more money. It's the old Dutch tulip speculation all over again. Buying and selling something that has an intrinsically low value for an inflated price as speculation.
Of course there are some who are buying them because the privacy value of using bitcoin is worth this risk. But it would need to be a very risky transaction for that to be the case....
Until we can have a market where the value of bitcoin is stable, where trading in bitcoin itself has the same effect as trading in ordinary currencies (ie. small movements driven by mostly external economic factors), then it will never be used widely to facilitate transactions...
I don't know how you get there though. I wish I did ...