Other than competition, easily bought out when you're working with a $600 billion valuation of Amazon, or loss of consumer interest, what incentive does a for profit company have to shift any gains from economies of scale/etc to consumers? Why not make your product for 10% less, charge the same, and pass on the difference to shareholders?
Apple is a great example. If they buy out the group making the M1 to reduce cost and improve supply chain efficiency, what incentive is there to lower prices especially for a company whose marketed image is all about premium? That money is going right into ongoing costs or to recoup the initial merger costs.
Any improvement to consumers are either hypothetical, relate directly to fending off competition, listed as bullets on a PowerPoint slide between VPs, or carefully constructed to pass regulatory questions, not to help their customers save money.