14 is a indeed very long. Let’s instead assume 12, it’s 2013 and you got a top specced T440 with 4th gen i7. That’s actually not bad and the build quality is like a tank as all Thinkpads. Nothing I would use as daily driver myself but having used many other thinkpads of that generation I can see why others are still getting by with it today.

Since we are talking about OS support. 4th gen Intel isn’t supported by Windows 11, so you’d have to upgrade to Linux.

I think we have different definitions of obsolescence. Mine is basically "the ability to continue to use the device for the original purpose that I purchased it for." In my case, developing Mac OS software (that's the only reason I own Macs, I do all of my day to day computing on Windows and Linux.) I completely agree with you that the hardware is in no sense obsolete, the software is a different matter. For example my original Retina iPad started feeling obsolete as soon as Safari stopped rendering modern websites, even though the device hardware does not feel obsolete. Another example is that every Mac Mini that I have bought was useless to me as soon as I could not upgrade the OS and run the latest XCode on it.

In my view the forcefull obsolescence mechanism comprises the following strongly interacting practices:

1. Not supplying operating system updates for "older" hardware (actually not that old). Depending on your security posture this point alone may be sufficient.

2. Aggressively deprecating APIs and nudging developers to use the new APIs (i.e. nudging applications to not support the operating systems that run on the older OS that you have to run on the old hardware -- see point 1)

3. Ratcheting operating system upgrades with new hardware. There is no way to control the OS version that you use independent of hardware: replacing a machine always forces an OS upgrade.

4. Requiring the latest OS to run the latest development tools.

In combination, these practices create a treadmill that keeps everything "new" and anything older than 3 years not compatible. There's probably more to it than this but that's what I could write down quickly.

Software drops support for certain OS versions even if the device still can run it.

The first iPad Pro can’t run adobe products for example.

The Mac is a bit more resilient to this, but it’s still worrying as yearly improvements become subtler.

I use Macs to develop Mac OS software. I need a recent OS to run the latest XCode and I need to test on the latest OS that my customers are using.