That's an issue with the overarching game design. Why this game isn't character oriented like Crusader Kings in an era where major events are driven by individual actors is hard to understand.
I disagree. They already have a character-focused game in CK3, and even though I'd love nothing more than to see a fleshed-out antiquity mod for CK3, Imperator Rome was supposed to be something different - not just another CK clone. Besides, it's more than possible to have a confusing UI in character-focused games, so that's not the issue here.
The game wants the player to manage an entire realm while removing any and all delegation of duties (you cannot assign governors to rule in your stead, etc. because you play as the "state" and are therefore expected to micromanage every aspect of your nation).
That is a fair complaint and I'm inclined to agree with you but that's pretty much the case with all PDX games. Hopefully, they'll give governors a bit more agency in the future, but giving them the option to control the imports/exports of their own provinces is a step in the right direction.
This game should have gone even deeper than Crusader Kings in regards to roleplaying as a single character. Orienting gameplay to such a degree would allow for more interesting storytelling
No. PDX already has CK3 which empathizes the roleplaying and storytelling aspect. Why have two separate teams develop two similar games? It would have been a lot easier, and more reasonable, for them to just make an antiquity DLC for CK3 than to make a brand new game. Would have saved them some money as well I assume. Besides, how could they have gone deeper into roleplaying than CK3? Again, it just sounds like you want Crusader Kings: Rome.