>As an example, in Jan 2026, Apple published iOS 12.5.8 which provides updates for iPhone 5s which released in Sept 2013. That's 12.5 years ago. The equivalent would be to connect to the internet using ADSL in Jan 2000 with your IBM PS/2 rocking in intel 8086, 512 kb of RAM and expecting an update for your DOS operating system.

The updates for ios 12 are all security updates, not feature updates, so your comparison to "connect to the internet using ADSL in Jan 2000 with your IBM PS/2 rocking in intel 8086" doesn't really make sense. The phones stuck on ios 15 are basically unusable because many apps don't support it anymore. At best you can download an older version from a few years ago, but that depends on whether the backend servers were updated. Apps that insist you use the latest version (eg. banking/finance apps) basically unusable.

IBM PC DOS 2000 was a thing that was published and sold. It would have ran fine on a system similar to what you describe. It addressed the only pressing thing in that space at that time that PC DOS 7 did not: Y2K compliance.

(I never had a PS/2, or ADSL, but I was goofing around with a low-memory 8088 box back then for fun. It had no hard drive. It bootstrapped from floppy, loaded the rest over the LAN with its built-in 10base2 Ethernet jack from my Linux box, and connected to dual-channel ISDN for Internet access. It worked. It even had a graphical web browser.

Being clever with an old iPhone is a very different thing.)

Indeed you can still get a battery replaced by Apple for an old iPhone 6.

The updates often require more power. Which drains the battery more than it was designed for. Which helps shorten the life of the device.

BTW: DOS was supported until 2001, and Win95 could boot DOS standalone.

Machines were roughly doubling in performance every year back in 2000.

Nowadays they are doubling in performance every... 5 years?