You can charge Teslas at other charging stations. It’s just that other chargers are inconvenient and unreliable. You usually need an adapter. You have to pull out a credit card and maybe install an app on your phone. With the Tesla chargers you just plug in and everything’s billed automatically.
Also Tesla’s navigation automatically adds charging stops for superchargers. You don’t have to do much thinking. Just drive the car (usually on autopilot on the freeway), follow the directions, and every few hours you’re at a charging station next to some restaurants, grocery stores, or pretty landmarks. The view from the charger at Twin Falls, Idaho is particularly beautiful.