[orthecreedence]

In a distributed system, which is often a place CRDTs thrive, deleted history means a new client cannot be brought up to the current state unless there is some form of state summarization. Doing this summarization/checkpointing in a consistent manner is difficult to do without some form of online consensus mechanism, which is also difficult to do in a distributed system with clients popping in and out all the time.

[josephg]

It depends on the system. Some approaches (like Greg Little's Shelf or my Eg-walker algorithm for text) make this trivial to implement.