It does a disservice to say the technology is already there, because it suggests that the current version is as good as it gets. To me, blockchain or something that incorporates its best features (decentralization, immutability) will need to process transactions for:
- Fractions of a cent - Confirm in seconds
So far that is not possible, and there is no clear way to achieve it, but with blockchain as a base there is no doubt that it will eventually be done. At that point, if you have not sacrificed decentralization or immutability, you have something truly amazing.