I'm surprised you mentioned iPhones, because that's exactly Apple's strategy. They tend to keep three generations around, and each time they introduce a new iPhone, they knock down the price of the previous generations. Here's [0] an article on them reducing the price of the iPhone 8 by $150 (from $559, so a significant cut of 25%) when they introduced the iPhone 11.

[0] https://venturebeat.com/2019/09/10/apple-cuts-iphone-8-and-i...