It’s less about ions “omitting” something (a matter of perspective) than about supporting an API. Right. The peer API is not over-a-wire friendly, thus we developed the cloud client API. Ions support the cloud client API. This lets people write portable production programs that run as clients (many people do) or ions. When running as ions you get peer-like in-proc perf, even with what looks like multiple “round trips”. Thus the decision to write ‘as if in proc with db’ (i.e. considering those ‘trips’ free) rests with the application, not the API. This is better, once wires might be involved, as only you know your deployment intentions.
Datomic cloud client’s query and pull results support datafy/nav. This can get you pretty far. You can see that in action in REBL.