I think Apple is more aggressive now in allowing older hardware to upgrade than it did in the past. The result is a poorer experience with newer devices at the latest supported version of iOS than in the past.
My iPad 1 (1st gen iPad) is still going strong on iOS 5.x. Performance and responsiveness is as snappy as it was the first day I bought it. It now serves as a digital picture tube for a vintage TV. (I gutted out the internals and replaced it with the iPad).
My iPad 2 (2nd gen iPad) is also working very well, but it is at iOS 7 (or thereabouts, I can't recall off the top of my head what the specific version is).
My Ipad 4 is at the latest supported version of iOS and it no longer performs well. My adult daughter has it now, and doesn't complain because it was free to her.
Air 2, Mini 4, and 12.9 Pro are all at the latest supported versions and run well... but only the 12.9 Pro still runs as well as it did with the initially shipped version of iOS.
Since Apple refuses to allow customers to downgrade to a previous version of iOS, they should either (A) be more conservative in which devices they allow to upgrade and/or (B) eliminate the obnoxious nag screens that an iOS update is available.
Before anyone replies that customers would "complain of planned obsolescence if they couldn't upgrade" there are far fewer complaints about NOT being able to upgrade than those who upgrade and are dissatisfied. Apple isn't doing anyone any favors by allow devices to upgrade to the latest version of iOS if they can't run it smoothly (with no way to back it off).
I totally agree, but this would quickly drive users to unsupported devices/apps.
Currently a developer can’t update apps for "unsupported" devices.
There is no way to build, update and distribute newer versions of apps for older iOS versions, and a sideload is also not possible. E.g. to rebuild and make something available with a newer webinterface api.
The planned obsolescence is not only a Apple issue, all these mobile OS devices, are done in a way to become unusable after 2-4years(sooner than later).
I find once a device become officially unsupported by a manufacturer, they should be legally forced to allow OS downgrades, sideload installs and device rooting.
E.g. I can still build Apps for older PC hardware or Windows versions, even for older macOS and Macs.
It’s up to the devs, what they want to support.
It’s one of the reasons why im slowly thinking of moving back to Windows.
This Apple eco system is nice, but slowly I’m not seeing reasons to upgrade my devices.
The main reasons i have are simply the mentioned limitations which is also a type of planed obsolescence.
In Brasil we to say to this: Se correr o bicho pega! Se ficar o bicho come!
Means: If you run the beast catchs you! If you stay the beast eats you!