I just wish that smartphones had a more standardised OS. Old laptops are fully usable in exactly the same way as a modern machine. They might be slightly slower. Well, I mean, it's getting more difficult to deal with 32bit hardware, but that's about 10-15 years old now. My 32bit atom netbook is still usable; still gets security patches; runs the latest everything (it's just very slow, and e.g. some distros dropped 32…
I ended up upgrading from T60 to somewhat newer, less-well-designed other ThinkPad series, mainly for a larger display, so that I wasn't tied to my desk as much. And I still transplant original T60 keyboards into the somewhat newer models, since, after the T60, Lenovo started making the keyboard flex.