About the argument that what Civ7 offers is more buildings per district, I guess that's both true and untrue in the sense that yes, you can argue that you can put two science buildings in a district per era where Civ6 only had what would be the equivalent of one science building each era, but then again, for the very reason that Civ7 offers more buildings for each yield and on top of that also offers all the warehouse buildings, the net result is sort of the opposite: You need more district tiles to hold the buildings in each city in Civ7 than you did in Civ6 - even more so because the district limit in Civ6 meant you couldn't actually build all buildings in each city, a limit that seems completely gone in Civ7.
So yes, I agree technically, but I at the same time think that if they Civ7 system is going to work, there needs a hard/harder limit on how many urban districts a city can sustain, particularly in the ancient era. Whether that is going to be a fantasy limit (similar to the settlement limit), limited by population (as in Civ6), limited by distance (i.e. ancient era can only have urban districts in first ring), limited by gold cost (i.e. soft limit), or something else entirely, I can't say. Personally I like the idea of a distance limit going up each era.