Not sure it's even useful to call it a "transaction" at that point, since nothing has been transacted. It feels like the difference between updating a value in-memory and committing a value to the database. Maybe you can hide the latency, but that hasn't removed the need to actually do the transaction, eventually, and now you have the added problem of managing consistency.
There are physical bank note, database from different system in trust or untrusted parties that need to be cross checked and reconsolidated