Tesloop, in one of its blog videos earlier this year, explained on its own example of high-mileage Tesla cars, how various reasons can cause noticeable battery degradation.
The company took its lessons from exceptionally high mileage of hundreds of thousands of miles per car, operating 8 out of 10 of the highest mileage Teslas in the world. Some of the cars - like the Tesla Model X 90D “Deuxy” are doing great, covering over 350,000 miles (563,150 km) on an original battery and drive units, with only 13% of estimated capacity/range fade. . . .
Some excellent charts, discussion of changes in SoC ranges used, other issues.