True...Due to my profesional background, I find myself staring too long at these graphs too. I love studying race telemetry and finding out what happened in turn 3 lap14, when engine temp started gradually going up (hole in the radiator!).
But it makes me a bit sad watching progress graphs spike right after grabbing some cities after a war, opposed to peaceful plays that result in much more discrete lines hidden between the rest.
Some general conclussions from my games (epic speed, king difficulty)
The overtake point is usually around the 120-160 turn area, regardless of peaceful or warmonger game.
Once I start having a high amount of gpt, I forget to keep purchasing regularly and mostly do bulk buys.
I am slow to settle, but by midgame (around T200) I start having more settled cities, and end up having between 5 and 15 cities more than the AI, which slows my race to the endgame significantly
My games end up being a bit too long because I spread and overdevelop too much, so my first half of a game is mostly flat progress, and the last 20 turns are supersteep, because I go from spreading resources and trade routes to focusing all in my most poweful city (usually chasing SV)
Still trying to improve my play, but I admit I have an obsessive need to make the best out of every city, and I end with 20-30 cities on standard sized maps around 10-15 pop the smallest 5, rest in the range of 20-25 and a capital with 25-35pop. Which I believe translates to super expensive districts and projects that could be avoided with a smaller sized empire and less ambitious cities.
About watching barbs on graphs. True aswell...Funny watching the first 100 turns there, where 9 out of 10 I havent been to any wars yet (or ever) yet the graphs show ridiculous spikes, only to settle gradually into a mostly flat, barely noticeable curve from T200 onwards.