We know that there is a calculation that goes into rated miles. We also know that conditions such as environmental factors, driving habits, and terrain can come into play when calculating capacity. Just like an ICE car, the "predicto-meter" will fluctuate as these factors change. I find it interesting that Electric Vehicles respond in a similar way to ICE cars yet we, as owners, do not perceive it the same.
Back in the '80s, there was a car made by GM that had a hyper-accurate gas gauge. On paper and in studies this seemed like a value add to consumers as they would know exactly how much gas remained would be able to make better fuel stop decisions. The reality was that people got stranded more often and the perception over fuel economy was very negative for this vehicle. As a result, GM went back to the inaccurate-but-familiar behavior of the old gas gauge. This gauge behavior still exists today.
Once I understood that what I was seeing was a much more accurate reading than I was used to, combined rated miles, I stopped worrying about it..