The examples are, literally, every device that uses a lithium ion battery. Take any phone or tablet, repeatedly charge and discharge the battery fully (better yet, do so in a hot climate) and eventually it will not put out sufficient voltage. This will either trigger CPU throttling, or your device will start crashing. The iPhone was the most widely publicized example, but this is a fundamental issue with battery chemistry that all battery powered devices are subject to.
It's not a question of if it's a question of when. All battery powered devices are subject to the limits of battery chemistry. Some phones have a bigger safety margin than others, but use the battery for long enough and it will put out less voltage than the device requires. As other commenters pointed out, other phones do indeed hit this limit.
That's a good point and Apple's phones failed much, much sooner than any other phones. Thus the reason we don't hear of the others.
Apple designed about a years worth of battery capacity into a phone most people expected to keep 2 or more years. And clearly they put too powerful CPUs into the phones because they "fix" is to throttle them!
The non-Apple choice is ... well, we all know the trade-offs there.
Are there any other phones out there that are supported with software updates as long as the iPhone? If there is an Android phone that's been used for 3+ years, it will be ba good data point.
Afaik, Android phone OEMs don't try to make a device last as long.
> - Designing the phone hardware with barely enough battery capacity, such that some moderately old phones might not be able to keep working properly when the batteries decayed.
Indeed! This was (and still is) very much a design flaw. People like to say, all phones have this issue, but where are the examples? Also, look at the iPads which are just scaled up iPhones. They don't have this issue because they don't suffer the same design flaw.
Apple put a bandage on the issue and people throw praise at them.