People in a third world country usually doesn't have their own bank accounts and this blockchain technology (bitcoin to be specific is making things happened) We users don't have to worry much more about setting up the wallets easy and free a lil bet of computer skills is needed.
I will want to disagree with that pending the time I will have more facts or you provide me one regarding Third world countries citizens not having bank accounts. Over here, if there is any sector that has developed over the years is the banking industry. Also with policies put in place and being introduced, a lot of people are coming into the bankers net and I tell you from here, anyone not there will definitely not have access to the computer which negates the impact you are proposing.
For me, the impacts has been about the trans-border payments without any bottleneck and very little cost of transfer to be paid in fees...