A car is expected to last longer than a laptop, and no-one needs to carry a car around all day in their back pockets. Also note that replacing the entire battery is the only viable way to recharge your Tesla quickly. You can charge your iOS device while you use it.
When Teslas have seen the kind of prolonged use and abuse people's phones and computers have taken, let's see how their battery packs do.
And of course, Apple sells battery replacements at pretty reasonable prices, but most people don't bother because depreciation makes it not worthwhile.
Our kids are using our original iPad 1s and abuse the heck out of them, and they still get decent battery life.