1: Output of single cities irrelevant in face of sheer numbers. Doesn't matter if you have one really good city you can more than make up for it with multiple cities at a far more efficient cost. Wonders don't really matter either. 2: Can be done if Civ 6 stops rewarding short term activity at the cost of long term investments. Making harvestables scale exponentially with Eras for example, makes harvesting a no-brainer compared with investing in productive potential etc. Making Eurekas and Inspirations give almost half the costs makes superior Cultural/Science output only half as advantageous. 3: Not denying possibility, denying competitive power relative to conquest.