As another example, for all the BYD fanboys - BYD's 'profitability' is in many ways at the expense of its suppliers who have to sign up for extremely punitive payment terms via the infamous Di-lian with significant discounts. What you call scale effect, I call bullying suppliers excessively. By the way this is why Shenzhen Inovance refused to supply BYD on its electric motors. As an aside, Di-lian has been colloquially referred to as the biggest illegal financing network since Evergrande by some in the industry.
Funnily enough I was going to respond and bring up this exact point.
We know for a fact, that auto manufacturers are squeezing up-stream suppliers, with BYD being the most prominent (because they are the most successful, and therefore with the largest market power). This isn't an example of "deflation through tech/economies of scale", this is just BYD taking money out of someone's pocket to put into their own, which does flow to the customer (presumably), but also reduces cash flow for their up-stream suppliers to expand and do their own R&D.
And I doubt that this is the only industry where it happens. In any case, the conversation is becoming far too dogmatic again. It just feels like people are looking for confirmation bias or positive trends rather than discussing the minutia of unpleasant circumstances.