I want to revisit early city growth, especially the snowy tundra start pic in the first post.
I've been given a similar start position a few times, but I have rerolled the start. Potential mines, sure, but where's the food?
How will my first city grow big enough to produce the first settler to produce a town on some grassland, to keep everybody fed?
Let's say the goal is to get the rough tundra capital to size 5 with a brickyard to start settler production. Brickyard would count for one population. After 2 turns you get 2nd pop for free in capital, so you're always at 10 food and need 69 more for 2 growth events to size 4. If you don't pick up any extra food (only 5 from city center), that's 14 turns. With 1 food on the first rural tile, that's 12; with 2 food, that's 10 turns.
Then you need to research Pottery (84 science on sovereign, 9 turns if you only have the initial 10 science/turn), and build a brickyard (55 production). If you grew to size 3 with taiga then wool, and built brickyard over the taiga to replace it with a mine (expanding towards iron), you now have 10 prod/turn for the brickyard, so 6 turns for the brickyard. Thus, time for pottery then brickyard is 15 turns, whereas growing to size 4 was 16 turns from founding without working any extra food. It would have been better to get some food on that first tile we built the brickyard over, since growth is the limiting factor here, but the difference isn't that bad. After this, first settler comes out in 4 turns at 14 prod / turn (5 city center + 4 wool + 3 iron + 2 other mine).
This is the worst case scenario, as for example you could get both food and science from discoveries to accelerate that timeline. One food boost is a great way to use an early discovery for a capital like this.
Once you grew enough to get to size 5 with the warehouse building, it makes sense to build over the food tile (if any) because we don't really need food in the capital after. It's not like previous games where population consumes food every turn (only specialists do). One way to see it is: once you can make settlers, why keep the food tile to grow one more size onto a production tile when you could get the production tile right away by building over the food? To gain something you would need to grow 2 more sizes in some reasonable time frame, but that won't happen with the current growth curve (we're talking over 200 food for the 4th and 5th growth events combined). Of course, if your leader, civ or map (e.g. natural wonder in capital) gives you lots of food or growth bonuses, it may balance differently.