> The big difference I feel going from old school civ games vs newer games is map tile improvements in old games you had to dedicate a unit to upgrading the tiles around cities (you would have units dedicated to permanently building irrigation, mines, roads and in late game they'd be on pollution cleanup duty to avoid global warming occurring). In modern civ they've abandoned this.

I haven't played Civ VII, and I don't think I played much of Civ II or III, but tile improvements is still a thing in Civ IV, V, and VI. In Civ I, the settler unit would do tile improvements and found cities, and at some point they switched to a settler that only founds cities and a worker unit that does tile improvements. In Civ VI, the worker only has a certain number of charges and then disbands, and they separated out road construction to happen with trade routes, but you still need workers to irrigate and add mines and whatever you need for special resources (in Civ I, there was one special resource and it was called resources; later games there's like spices and bananas and coffee and gold and what have you)