Think of things like the introduction of cars, or the internet. Their actual effect on most people weren't a matter of obvious problems they had at the time.
Cars weren't released out of the blue by a well-funded startup as a half-baked MVP, they were built off of advances in industrial metallurgy, the invention of the engine, engineering used in trains and boats. Similarly, the internet didn't just happen - people first figured out electrical engineering, circuit boards, GUI's, COBOL and C++ and a myriad of other languages that made it possible to invent the internet.
I'm not saying that this online bank thingie is on that level yet. But for me, these kind of inventions are indicative of the death of institutional finance. The first step in destroying global finance as an institution is to whittle away at where the banks can make profit. Apps like Robin Hood have already helped to decentralize knowledge and participation in the stock market. Cryptocurrencies like Bitcoin have shown at least a proof of concept that you don't need central banks to have currency. Money transfer apps like TransferWise eliminate currency conversion profiteering. Now what happens when you make a front-end that can wire all of these ideas together? A cashless society? Maybe.
I would also say that if you'd told people about those problems thirty years ago, people might have responded 'but I can already communicate with my team using a conference call' and 'I can already sell items through the classified or flea market'. 'What new problems are these things solving?'
I think that most inventions don't do anything particularly new - the kinds of individual tasks you can do with them could have been done before. What they tend to do is provide greater efficiency. And greater efficiency at scale enables new kinds of things to happen.
E.g. think of youtube. It was possible for people to share videos before the internet. E.g. you could have submitted a description of your video to a printed catalogue, and if people wanted to watch it they'd contact you via the catalogue, so you could send them a copy on VHS. What youtube and the internet does is makes it so much easier -- so much more efficient -- that it makes it practical, and the scale enables all sorts of new things to crop up on top of it.