My grandmothers iPad 3 has become completely unusable because of throtteling, whether is is plugged in or not.
iOS does not adjust battery-related throttling (whether low battery, low power mode, or battery wear) based on if it is charging.
Same as recent macs.
So yes.
Thanks - that is really interesting. So Apple designed the system in a way that definitely hides deteriorating performance due to throttling from the end user? Can you point to any documentation that validates this?
Apple doesn’t officially document that, but see various support discussions: