Most people drive more than X miles on Y% of their trips. For any given (X, Y) where Y is non-trivial — and 5% is non-trivial for most people — you can augment

Most people drive more than X miles on Y% of their trips. For any given (X, Y) where Y is non-trivial — and 5% is non-trivial for most people — you can augment an X-mile battery limit by adding public charging stations. However the smaller X is, the more numerous and densely spaced those stations will have to be, which is deeply challenging given the layout of roads, and the cost of building charging stations. (This leaves aside the relative annoyance of making many brief stops vs. occasional longer stops.) Manufacturers like Tesla control both “X” and the charging station layout, and have limited influence over “Y” except insofar as it affects their ability to sell cars. Presumably they’ve crunched the numbers and concluded that they can’t support a reasonable customer base on small values like X=50.