Duniter is not following that road either. Also Ğ1 (pronounce « June ») is already launched, we won’t completely change the core concepts now. We have studied IOAT and think it is not adapted to Duniter (it could, but the cost to change to this architecture will delay Ğ1 growth to 2048, and the benefits are not obivous).
Finally, we don’t have to do anything. We have studied the pros and cons of the blockchain, for example here is my analysis of the blockchain concept, and we only make choices based on these studies.
Blockchain is definitely a good solution to have a commonly shared database. Other solutions can be found, but blockchain is really OK to us. I don’t see any acceptable reason why this solution should be rejected.
Should I recall that Duniter’s blockchain != generic blockchain, because it is based on the Web of Trust.