clean install: you make a backup, nuke the computer, install a fresh upgraded copy of the distro you want from a live usb, copy your data again to the computer.
upgrade: you wait ‘till the distro’ developers release an upgrade you can directly install from your soon to be old distro, you use a command like sudo do-release-upgrade
and why do you upgrade like that?
Well, I also use a rolling release distro, my disk died last week so I had to reinstall, so technically FULL hardware update might require a reinstall (safer than copying the root folder from one disk to another since the old one was bad), but yeah, before that I’ve replaced almost every piece of that laptop without a reinstall, even switched from Nvidia to AMD.
Well, yeah. Hard drive failure can force a reinstall. And with laptops there isn’t usually another place for a hard drive, from where to restore the system.
Brainfart, I said laptop meant desktop, obviously didn’t change the GPU on a laptop.
*Framework has entered the chat*