and I'm confident 99.99% of civ players don't want a historical simulator
Well I must be one of those persons among 10000 that wouldn't mind it.
Realism is IMHO a good fuel for new gameplay ideas.
Obviously it wouldn't be a "replica", anything approaching it would be movie, in a very limited time and space, and yet, with inevitable romance to fill the gaps. Or, a book. We've seen books that try to tell the whole history of mankind, or even encyclopedias, but I don't think anyone nearly approached to describe the world from every points of views. (spoiler : it cannot be done)
However we can make a simulator that simulates more or less the behavior of civilizations in different contexts, and the better one would be the one that with x actions at y times, it would unfold like the real history or something vaguely resembling in the context of the gameplay rules. Now push off a little sand grain at the start or in the middle, and everything becomes different. Not talking about playing on a random Pangaea map. The game would unfold totally differently than reality, especially if the player is involved, and it would still be a "simulation".
In fact, if it were not for the encouraged randomization from the start in new game settings, Civ would already be a simulation. Scenarios however generally introduce new rules and narrowed time and space, for them to be easier to "reproduce" History. Every iteration has its scenarios.
Don't get me wrong : every random game with such an engine would be so different than reality that it becomes irrelevant to create it, because the results would be equally different. But, as I said, it could be, it *is* an inspiration for introducing new mechanics ; for example : a while back I was watching a YouTube video of Marbozir playing France on a true Earth map (Civ5). He spawned in the middle of Africa, and soon colonized Madagascar. I said myself : "Madagascar doesn't look quite endemic like it is in reality, for example what I know of it is baobabs. Where are the baobabs ? Where is the diversity ? Every parts of Earth look the same, it's too bad". Now, it is uncertain implementing more diversity would serve good gameplay ideas, but, from one thing to another, we can elaborate ideas that would have an impact on gameplay or atmosphere.
On atmosphere because I will not buy Civ7 principally due to its claustrophaubic ambiance of cities sprawl. Maybe it's a view of exageration just to say something, but I feel the graphics are too baroque, not cheerful enough. Earth is not about mechanisms and cogs, it's about Nature before all. We are a part of Nature, Nature is not a part of us. We cannot live without it, and as we destroy it few by few, we are digging our own grave. That's a message that existed in previous iterations, but I'm not sure it will a part of the vanilla version of Civ7. If it is forseen for the expansions, then I fear it will be fatalist and we will have no choice than to confront the apocalypse, given how nature seems oblitered by cities sprawl in vanilla.
On gameplay, Civ7 invented the exploration era, with its unknown lands to be discovered, that loot to get, etc. And, in some form, the rise & fall of civilizations. Where do you want to pick your ideas if not from reality, History ? If you want only strategy, stick to Chess. (but, unfortunately, horsemen can jump above obstacles)
If you want to stick to strategy only, ideas would be totally different and there would be no way to make a series of it, except by refining the rules over and over, until total drying out after 2 or 3 episodes. On contrary, Civ series never cease to raise expectations, hence the enthousiam and even more, I would say, the disillusions.