Honestly, there's probably a reasonable cost analysis to be done to determine whether or not Tesla should farm out its charging stations to other auto makers as well.
Tesla has already stated it would provide others with access to the Superchargers if they built their EVs to be compatible with them. As far as I know, no one has gone anywhere with that offer.
Of course, you have to assume that Tesla would charge for that, and the auto manufacturers would have to roll the cost into the cost of a car.
The Supercharger network is getting better every day. The longer other automakers delay doing something serious in the charging space, the more inevitable it seems that everyone's going to be paying Tesla to use its chargers.
Tesla's huge competitive advantages, imho, are: 1) the battery supply chain it is building for itself (and maybe some friends), 2) its wonderful supercharger network, 3) software that is several leagues above the competition, 4) a reputation for building superb products that "wow" people, and 5) a reputation for wanting to serve customers in a direct, honest way -- not just take their money. Excluding the 2 subjective points at the end, I'm not seeing another automaker offer something comparable for 1, 2,
or 3, let alone 1, 2,
and 3.
What that means is: they simply aren't serious about electrification, or they are far too slow-moving to compete. In either case, it looks like Tesla dominates the future of automobiles.
My 2 cents.