But I think the biggest barrier is most FOSS enthusiasts consider web apps and collaboration to be anti user malware.
1. A generic CRDT library, preferably in C or something that exposes a C interface. This is probably very hard or even impossible, depending on how much must be abstracted and how much work the developer must do to express edits in terms of the CRDT.
2. A P2P backend for said library for streaming edits.
3. A networked data store, maybe as-a-service, for versioning and persistence.
2 and 3 might even be made transparent to non-CRDT-aware applications through FUSE, but that's not a hard requirement.
It was removed because no one wanted to maintain it.
It's not impossible to imagine it being added back in though. Maybe with updated technology.
It does require someone to maintain and pay for the cloud hosting. That shouldn't be unsolvable; that's not really any fundamentally different than hosting a download site for traditional FOSS. Donation-supported FOSS can work.