You don’t have to throw away your old PCs and laptops. Install a lightweight Linux distro on them and they’re as good as new. Lightweight distros don’t even have to be used on old hardware. You can install them on some bleeding-edge hardware and get the ultimate performance. Most distros are portable and can run on a Live CD/USB, without a hard drive. Why should you use other OSes full of bloatware and unnecessary stuff when you can use a perfectly fine Linux alternative?