OT systems generally require a single, centralised server to be a party in between any two changes. CRDTs make it really easy to do multi-server deployments or peer-to-peer data replication. That is (basically) not possible using OT based systems.
Oh, absolutely. And OT based approaches work great here. CRDTs have the advantage that multi-server deployments are also easy, and modern CRDTs are increasingly faster and better optimized than most OT systems (certainly the ones I've worked on). But OT is a great approach.