Digital currencies have now been around here with us for quite a little long time. For some, it's an old thing, for some it's a whole new scenario. Now, as per my opinion digital currencies have solved our numerous problems. They've given us advantages in plenty amount.
(1) They solve problems of theft and stealing, (ransom and kidnapping may exist though)
(2) They have made transactions possible from distance and quicker than ever!
(3) They provide you more secure wallets. (Your leather wallet in pocket can be taken out easily by someone, not in case of digital currency.
The security issue is actually pretty big in bitcoin. If you keep your wallet on your computer, and there is a rat on there then you're pretty much fucked before you even start. However offline wallets are available, but that investment would be too much for some people.
As for bitcoin solving problems. Yes math problems, they are the hardest earth has ever seen.
And here I have to agree.
The question arises whether Bitcoin is for everyone?
People with experience in IT make mistakes in securing wallet.
People who do not have a computer-related education have practically no chance to protect from thieves.
Cryptocurrencies become popular if they are created tools to safely operate them.