No, let's be honest. CEPH is the only solution for data management at this scale (sub to few PB). The solution which is independent of application or workload. The market share, fact IBM is moving people off other projects internally for this, and the massive backing shows this.

Yes you can have all or a bunch of these features like failure domains via other routes/products but none have all of the stuff together in one place like CEPH.

There's a reason people call it the "Linux of storage". The only alternatives are manage this at a higher level in your stack (reinventing the wheel) or buying PB level solutions from corporate which is like saying I'm buying Oracle and MS over Linux.

Protocol replication means you've reimplemented something which is storage related elsewhere in your stack. It's not incorrect to do so, but there exist better solutions and alternatives now.