They of course stop updating old devices. The 5 year old iPhone XR is getting updated to iOS 17 this month, and they are still putting out security updates to the 9 year old iPhone 5S.

They started limiting the CPU clock on older devices that had poor batteries in situations where it would try to draw more power than the battery could maintain. Identical devices with good batteries were not slowed down. Literally the opposite of planned obsolescence, but they failed to communicate what was happening which very likely lead people to buy new phones instead of getting their batteries replaced. At that time I had an iPhone for personal use and a Galaxy S5 for work. The S5 started doing the exact thing that Apple prevented when my battery started wearing out and random apps would crash the phone. However, unlike Apple where I could pay them $99 to fix it, Samsung and Verizon essentially told me to go pound sand and wouldn't even sell us an official battery. We resorted to buying some sketchy thing off Amazon that never seemed to be as good. Kinda funny how Apple got all the hate, yet Samsung was the one that let me down.