> Like, wasn't this what the legacy auto manufacturers learned in the 90s as competition ramped up from Asia, that it really wasn't worth the diversion of having half a dozen barely-differentiated cars on the same "platform" being badged and marketed in different ways (think Taurus/Sable/Continental, etc).

Volkswagen is a top 3 auto manufacturer and was top 1 recently. Volkswagen, Skoda, Seat, Audi go exactly against what you're saying.