Without commenting on the CB2077 vs R&C discussion (i think they have such differing art styles and scopes that they are difficult to compare), I just want to say that I don't think high detail models are a good bellwether for whether something is last gen or current gen. Model quality within games will vary vastly depending on the scope of the game. Car models in the latest PS4 GT game for example would be far more detailed than those in GTA5, and perhaps even beat out those in GTA 6. The lead character models in say Uncharted 4 may well be more detailed than the NPC's in GTA6 and so on...
Potentially streaming would allow piperun assets to be used in open world games. Like ratchet&clank removing stuff behind camera and using all ram to render visible things. UE5 is good example of this as they claim they can use source level assets and do lod dynamically. Storage space becomes bigger problem than bandwidth needed to stream. Who is going to make first game taking more than 1TB space?