According to this link, in a letter to Congress, Apple said that they were now using "a more advanced hardware and software design" such that the "impacts of performance management may be less noticeable." Note the words "may" and "less". https://bgr.com/2018/10/31/iphone-x-speed-throttling-may-occur-as-the-battery-gets-old/ There is now a preference setting for disabling throttling. The implicit tradeoff is that disabling throttling when you have an aging battery may increase the risk that you will experience unexpected shutdowns. EDIT: If you go two links deep, there's an article claiming that CPU throttling is a thing of the past. But that very same article quotes the Apple letter (which leaves the door open for some throttling), suggesting that the reporters did not fully understand the news they were reporting on.