Mods don't disable achievements.. And even if they did, most casual players aren't exactly the type to engage in finding mods.
The numbers are fairly consistent with Civ 5's too. And anecdotally speaking people I actually know don't play civs on high or even mid difficulty either because of the handicaps.
Sure people don't finish games, but I think people are overestimating overall skill level of not just civ but gaming in general. Many people just don't take gaming seriously, and the people that actually do are by and far in the minority. Even in games with competitive content often will see a fairly low average skill level, much less a predominantly single player game.
I mean to people that have played civ for many years, it may seem easy, but that's just not that common. I wouldn't doubt that civ 6 is an easier one, of course.
Thing is, the very thing I was speaking of with regards to playing on Emperor is this very sort of scripted approach: always pick Magnus, always give him such-and-such promotions, always pick this policy followed by that one.
You really don't need any of that. As long as you don't die early on, your start isn't complete crap, and aren't meming, you really can't lose on Emperor because the AI simply does't know how to win. I have many games where I have
2 cities @ turn 100 (yea I don't give a damn about efficiency), sometimes even later, and yet the AI is nowhere even near any form of victory when I finish the game some time before t300. Hell, even the deity AI struggles to win at that time and the tech pace is faster. Fact is, the challenge in the game is simply about overcoming the mechanics, rather than outplaying the AI.
Now it's entirely possible to get very bored and quit via apathy. But that's not really the same thing.
I do agree that chopping needs to be nerfed and have disdain for that. The dominance of certain units and chop abuse does indeed kill off much diversity. And I also feel there are so many things in the game that just have such an awful ROI. Hopefully GS fixes that.