Replace the HDD with a 512 GB SATA SSD, install 8 GBs of RAM and it will probably last more
nah, it would seem more magical when in 4 years his great uncle magically upgrades his pc to be light years faster. Had this experience as a kid, totally worth it.
I am glad that you are at peace with your workstations now, but just for updates on current situation in Linux Desktop world:
Glad that Linux have noticeable progress in its lifespan