VW certification is not too expensive compared to DexosD, or Dexos1gen3. Often cheaper oil like Supertech Walmart, Costco, or Amazon Basic with Dexos1gen3 use straight from tested combo (base +additives package) from Lubrizol, Afton Chem, Infinium, or Oronite. Therefore, they don't need to pay millions $ tests, just pay a bit royalty instead.
VW, Benz, BMW, Volvo oil certification cost is not astronomical in lubricant industry. Fortunately we have the generic ACEA standard like C3, C5, or older A3/B4, just like API SP, SQ,..
It benefits us in pricing and less marketing, royalty costs.