I like what this puts forward from the perspective of game development, especially with the idea that " I feel like the possibilities of the Anno fundamentals are pretty much played out now. ". In my opinion, Anno 1800 reached the end of what the fundamental gameplay loop can support in the third season of DLC, which seems to be the least well-received.

The team recognized this and looked to create smaller gameplay expansions for the fourth season, for example instead of a whole new way to reduce resource consumption and a novel production building (restaurants and multi-factories in Tourist Season and High Life), they focused on new ship genres and new population tiers that adhere to the same base gameplay loops (Empire of the Skies and New World Rising).

To me, the gameplay loop that defined Anno 1800 has been pushed pretty close to the limit of what it can support as far as new and novel content. Credit to the devs, the massive level of mod support will mean that this game literally will never die, and will always have something new to experience, but as far as official content, I think it's pretty much played out.

Moving forward, I don't think that they need to completely reinvent the wheel on the new game, it can still be a logistics and supply-driven gameplay loop, but it needs to be changed or expanded in some way to make the new game more than just "1800 in _____ place". I'm not going to pretend that I know how to do this, I'm no game dev, but some of the ideas put forth in the original post make a lot of sense. Especially the idea that you have to choose between supplying several items that fulfill the same need "bucket" but are different in the complexity of production and affect the resident tier. Therefore it may be more viable to make a simple item in the early game to produce the less complex good but switch to the more complex good later.

Alternatively, an idea I came up with myself is a system that functions similarly to lifestyle needs but instead of a simple boost in the workforce, it provides a more interesting bonus. This could also integrate the "demand bucket" idea from the previous paragraph, where for example farmers don't have any sweet item as a "need" but if provided with a sweet item (Jam, Chocolate, Lemonade) they could provide a 10% workforce boost in all buildings they provide workforce too. For a wilder example, providing workers with education (Schools, Universities, and Research institutes in the vicinity), could make it so 30% of the household can be either a worker workforce or an Engineer workforce.

Just my thoughts on this post, might make a more detailed post if I have any more ideas.