> If the transaction fails due to a conflict it can usually be transparently re-tried
True, but if your transaction is retriable in that way then you might as well write the initial request and then do the processing async afterwards (i.e. event sourcing style).
I mean synchronous retry during the same request on conflicts with concurrent operations. Async processing is usually not an option, because then you can't return the result in the current request. Also retries can fail, which needs to communicated to the user.
