> ...none of the major incumbent automakers seems to pose much of a threat to market leader Tesla, which has become nearly synonymous with EVs.
This is only true in the US. In Europe VW and Renault have cut into Tesla's lead, and in some countries VW just overtook Tesla in vehicles sold. In 2020 the Renault Zoe outsold the Tesla Model 3 in Europe.
> But imagine if, instead of investing tens of billions of dollars in producing cars with no way to drive long distances individually, Audi, GM, Ford, and the rest each spent just a billion dollars to build a network of supercharging stations.
They have. BMW, Daimler, Ford, Hyundai, and VW collaborated to build out the IONITY network. VW is also building Electrify America (albeit as a result of Dieselgate). Non-Tesla DCFC stations far outnumber the Tesla Superchargers now.