I've only played a couple of encounters so far but this pales in comparison to Returnal: Ascension and GOW: Valhalla. At least, in terms of narrative through line, which I feel would greatly benefit No Return. Returnal's DLC has the first person story sequences, many scout logs, new dialogue from Selene, 20 xenoglyphs and multiple xeno-archives. Valhalla has all new dialogue from Kratos and Minor, new cutscenes, new dialogue and interactions with the Valkyries, etc. It's not the case with No Return.
You mention what could have been, and I agree. You know what else could've been, why not have different storylines for each character? Jesse in shows up on the base game outta nowhere to help Ellie. Why not have his run fighting from Jackson to reach Ellie? The same thing with Tommy. How about playing as Joel with Tommy doing runs and having to check in at safe houses? How bout having a cut scene with Maria giving your character orders to go a a run to retrieve some specific supplies that Jackson needs that someone else scouted and now you need to get it?
They could've had you play as Joel with Tess going on smuggle runs in Boston. You have to complete a job for Robert. They have the assets from Last of Us Part 1. And why can't we travel from location to location? You chart your course from the safe house which is good. But why are you returned back to the safe house? Why don't you have control? We should be able to travel with Shimmer, the horse to the next location to keep the rhythm of the game flowing instead of this endless affluvium of loading screens.