Apple has been proven to intentionally slow down older devices, but it's definitely not to inflate their profits. It's just a way to kindly preserve your old battery for you. And they try to keep it a secret from you so you don't get confused.
… Eh? It was neither. It was due to a design defect in a particular model; if voltage fell into a range that was perfectly possible with an aging but still functional battery, the SoC would shut off. The only viable software fix was to clock it down instead (there was an option to decline that and risk the abrupt shutoffs).
Not really sure what else they could have done there.
It's not a particular model. It's every model. And it's just interesting that no other manufacturer seems to have the same problem. iPhones are just too advanced, I suppose.
My old iPhone 7, before I eventually replaced it, would sometimes just die due to this as the battery aged (I kept the slowdown setting turned off). AFAIK it is _not_ a thing in any version after the 7 (or maybe 8?); certainly my 11 had a significantly degraded battery by the end (I kept it for four years), and didn't suffer this issue.
EDIT: Actually, I think this article is a _little_ inaccurate, or at least confusing:
> thus preventing the handsets from rapidly running out of juice and powering off.
IIRC the issue was, more precisely, that the SoCs had insufficient voltage smoothing to reliably tolerate full power draw at lowered voltages, and would shut off randomly. I assume the fix was, pretty much, more capacitors.
