

They get updates, that will gank your device and make it unusable. Ask me how I know this.
Are you talking about the underclocking?
There was a generation that included many faulty batteries that caused undervolting. An undervolted CPU simply stops, causing the phones to shut off. The solution for those phones was to detect the battery lifecycle and underclock the CPU so it wouldn’t undervolt. For any phone affected, Apple offered extremely discounted (if not free) battery replacements, which would restore the CPU to original clock speed.
I was an Android user at the time, and people were accusing Apple of planned obsolescence and decrying the underclocking, but it seemed like a solid solution to a faulty battery issue to me.
Now, iOS tracks your battery health. If the battery has less than 80% battery health in the first, like, six months, it means a faulty battery and they will replace it for free.
I’m aware, I’m quoting an episode of Archer (which I believe itself was referencing something else).