How can there ever be factual evidence that Apple has slowed down old devices on purpose? Even if we had the source code, showing an algorithm that would in effect slow down older devices specifically, the programmer could say it was a mistake.
The absence of hard evidence of motive doesn’t mean something isn’t true.
Likewise, it’s also wrong to say that there’s hard evidence to prove they’re NOT doing slowing older phones on purpose.
All we know for sure is that older phones get slower. The question is why.
What frightens me is that many people on here (like yourself) claim they’re 100% sure in one direction, and then think they’re being reasonable and logical by saying so.
Apple has every reason in the world to slow down older devices. The counter argument that they wouldn’t deliberately sabotage devices they no longer sell, as it would negatively affect their brand, is proven false by the fact that this already happens, and their brand seems fine.
Likewise the idea that the entire system needs to run slower on older phones so you can have new features like animated emojis doesn’t hold water. Adding Siri to MacOS doesn’t make Mail perform worse when fetching emails. They’re unrelated.
Finally Apple will do plenty of internal testing across all supported devices. They’re well aware of all slow downs... but they don’t fix them. How can that not be considered “on purpose”?