Ford never dominated the US market for gas stations like Tesla does for chargers. Even if Tesla never builds another charger outside the US, it can thrive by dominating the US market alone. And the experience of EA and others demonstrates that it’s not so easy to set up a competing network.
Of course Tesla might spin off its charging business, but that won’t worry investors. It just means that your Tesla share would turn into a share of TeslaCars plus a share if TeslaChargers.