I think you may have accidentally nailed the problem (we have a similar one in the US) and that is the Digital Divide. There are a large number of people without access or use for internet and computers generally. There is a bit of a bootstrapping problem with this whole class of migration issues in that step 0 is, get everyone using the internet.
I also think you're right that crypto has a unique advantage that other businesses will not be able to take advantage of easily and that is the brain-wallet or paper-wallet. The thing with non-digital folks is that computers are not part of their daily lives, hence the use of cash. Crypto can be cash-like in that there are no agreements or monthly bills while still being able to be kept in one's wallet, so to speak. This isn't a fully fleshed out idea obviously, but hopefully the potential is clear.