Why does Apple think it needs to slow down old iphones but other manufacturers do not need to do it to their older smartphines?

Why does Apple think it needs to slow down old iphones but other manufacturers do not need to do it to their older smartphines? - 1

I don't know. Maybe people like only the newer products from Apple. Such as iPhone 10, iPhone 8 etc.

It is not the age of the phone, it's dependent on the state (capacity) of the battery.

If the battery total capacity is low due to age and use, the phone slows down to use less power - helping extend battery life.
Fit a new battery and it returns to full performance.

New batteries cost 10- or less on ebay and are pretty easy to fit.

Apple have admitted what they do and there may be some genuine merit in it other than nudging owners to upgrade "tired" phones which are in reality perfectly good but hobbled by that trick.

But in my experience, I'm absolutely certain that other manufacturers do very much the same and would use the same excuses as Apple.

Other manufacturers haven't said that they do or not, but that doesn't mean that they haven't already & just keeping it quiet. Samsung in particular does more of its questionable decisions quietly, like the time they were caught cheating at benchmarks or during the whole Galaxy Note 7 debacle where they were trying to keep affected customers quiet about it.

My thoughts on the whole Apple/older iPhone thing is, its not as bad as it looks, but Apple should have been more upfront about what is going on.