Their strategy was to build them where there weren't other dcfc chargers, opening up new areas especially around outdoors places. Their chargers are much better maintained in general than the infamous Electrify America (they really struggle to fix EA chargers when they have problems, and they have problems) - there's a long story behind this. Rivian started before the plan to use superchargers was even envisioned, so…
Tesla’s magic is excellent, quick, and cheap manufacturing coupled with their own dedicated software for them. And constant iteration. EA is a pathetic failure because its a hodgepodge of outsourced components (so very difficult to iterate) running on some shitty outsourced windows based software.
say no more