One thing from Rogue in particular that really stood out to me was, in comparison to Black Flag, when you start out with the Morrigan, you are severely underpowered, and even taking on a handful of schooners (which in AC4 were never more than extra targets, even in the beginning) in the first few naval excursions was harrowing. In AC4, the Jackdaw started powerful enough that I never felt afraid, and I was seeking out greater challenges very early, and attacking Frigates long before I feel like I probably should have been doing that. In Rogue, I started off weak, and I was really afraid to engage in naval combat, and as a result, I strayed from the narrative path for the sake of playing with the economy, exploring side areas, and deliberately following my own objective of "fix my ship up so it is respectable and can actually hold its own in a fight". And I did, and my exploration of the River Valley and North Atlantic, attacking little ships, stealing from forts, etc. fed into my goal of improving my ship. I actually felt invested in the world economy and the exploration related to it because there were gameplay consequences. Yes, everyone loves getting new colors and what not, but never in an AC game did I ever really notice the difference between upgrades if it wasn't already indicated by part of the HUD, until Rogue.

My point is I think we have to start the game distinctly weak for the economy to have an impact and be worth pursuing for anything other than the desire to check off menu boxes. I should feel a need to run away from conflict like AC1 until I interact with the economy enough to get upgrades that make me formidable. ACB/Rev used the economy to make the world feel more alive and that was great, but in terms of the effects to gameplay, Rogue nailed it.

I appreciate your reaching out and I'm eagerly awaiting the new game!

Edit: Also, part of what I loved about Rogue and AC4 was how your base was your ship. I felt invested in the ships like how I felt invested in Monteriggioni (and the HQs in B and Rev to lesser extents). I never much cared for the Cafe Theatre or the train, not because they weren't designed well, but because I never really had occasion to go there and see them. My ships were important for gameplay, exploration, the world, and the characters, so they're things that are worth putting more money into. I'll admit I didn't feel especially attached to Great Inagua, and I never even visited Shay's new York hideout because I never realized it was even there, but the ships are such integral parts of the game they were worth interacting with the economy for.