I'm trying to understand it the same. How is this different to them saying "you have to buy airline tickets via a travel-agent?", or "you cannot buy from Intel, only eBuyer?".
Does car company now have less power? ( with subscription and OTA updates , I think they have more power than ever)
Yes, we do. The "Big Three" of Ford, GM, and Chrysler now face significant competition in the US from Japanese, German, Korean, etc. carmakers.
All new electric car companies too
Tesla and Rivian, for example, wouldn't even be able to exist without this, the cost of setting up new dealerships is enormous otherwise.