I don't know why some people tend to lean towards switching to percentage and leaving it alone. Probably because Tesla has us conditioned into expecting the loss of miles. My 2020 performance was supposed to give 348 miles on full charge and app. 310 miles at 90% charge which only lasted for for a couple of week. After a couple of week it dropped to 338 miles and is now at 328 miles lol so yeah switching to percentage takes that headache away, however, it's like taking care of the symptom and not the problem itself. I wish this severe drop in miles won't happen but then again it's probably unrealistic and may be other EVs have the same issue
Several reasons, and none of them are because I'm conditioned by Tesla, I can assure you. It's no different than ICE cars range estimates (worse, actually), which I was already well aware are completely unusable. My previous Audi S5 sportback reported a range of 320 miles every single time I filled it up. Within 20 miles it was always down in the mid 200s. At best. Even if I literally drove it from gas station to gas station using nothing but highway while driving the rated speed, I would never get 320.
Tesla's rated range is even MORE inaccurate, because it doesn't factor parasitic power drain from things like sentry mode and summon quick start. Those are a significant factor in how much actual mileage you can get out of a car, especially if you mostly drive it around town. Add to that the variables like elevation change, wind direction, speed, traffic, temperature, and a whole host of others, and it just makes the rated range displayed when you charge the car completely useless. I get in the car and it says 300, but one day I could drive 20 miles and see 275 left, and the next it might show 265 left. It's just not useful.
The
only way to get a useful measure of range is to plug in your destination and see how much battery/range the car estimates you'll have when you arrive. At least that factors some of the above, and can usually be mentally adjusted for things like driving speed (e.g. I know I'll never make the rated range because I typically drive 75-80 in a 70 zone).
I don't watch the battery meter either, tbh, but at least I find it useful to know what percentage I'm at relative to a full charge.
Regarding loss of miles, yeah, it's a factor, but not that much. Software version and season (temp) often have a much larger effect on rated range. I track mine with TeslaFi, but much like my ETF portfolio, I'm not checking it every day.