That is a little difficult to answer, as the scope is really wide. There are multiple layers of regulation in almost everything that we do today. A simple thing like paying by credit card has to go through a pre-approved network of the Point of sale Device provider, the issuer of the credit card and the aggregator (Master, Visa, Rupay, Amex, Discovery etc). So imagine two scenarios here. I use an Axis Bank card. I visit M K Retail for my groceries and they bank with ICICI bank. So when i swipe my card, in an instance the point of sale machine pings Visa to ask if I was issued this card bearing a specific number and if i have enough credit left to honour that payment. Now imagine i am still using the same card and am traveling overseas and wish to pay at a restaurant. In the first case, it is a domestic payment and will only pass through one loop, as against the second payment has to go through two as it a FCY payment. All this data is stored and verified only after the RBI approves the use to all three stake holders. So, technology is not the biggest challenge in financial services. Millions have have been invested and are being invested as we speak to automate this sector.
Also, I have seem way too many scams first hand, from a few thousands to a tens of crores to know what people do to avoid the legal and regulatory framework. So, it is not so easy to say that i want to disrupt something without the regulator breathing down my neck.
My guiding principle would what you said to me once, don't be naive to say that just because i am not aware of something, doesn't imply that someone isn't doing it or hasn't tried. Go down the path completely, make extensive research on the idea, speak to the regulators if you want (they are actually pretty approachable) understand why someone hasn't disrupted the current world order. Then take a call.