For me, the EPA range numbers are important because I'm in the market to buy a new car later this year and I'd like a fair gauge to compare vehicles on expected milage (part of the reason is wife has mileage anxiety, which I believe a lot of non-EV people have as well).
Looking at the first article the lead commenter posted that compared "real-world" to EPA ranges, Tesla misses the EPA range by an average of 22%. Other vehicles that miss the EPA range average 4.5% off.
Of course the EPA range is as much an estimate as the testing is and conditions change between testing and real world scenarios, but what's so different with the Tesla vehicles during EPA testing compared to real-world testing to cause such a large drop-off compared to other vehicles.
We can rightly question the EPA testing methodology in the first place meaning, what are they running (or not running) that regular people would. For example, does EPA not run the A/C during the test? I'm not accusing the Tesla A/C from excessive battery draw, as it's just an example.
Yes, having a larger battery is welcome, so with an EPA range of 400 miles, then we can real-world expect 320 miles.
*Quick addendum: I'm not a big fan of these types of articles and can more then accept that the testing the article performed was "flawed" as well. But we do need better, consistent range tests.