If you're looking for a distribution for an aging machine and you want to go with something other than a Ubuntu-based distribution, walk through the Arch with Omega.
BunsenLabs Carbon is a mishmash of Linux desktop components, which shines through when you go to customize the desktop.
Rockchip RK3588 and RK3576 get mainline Linux support for H.264 (AVC) and H.265 (HEVC) hardware video coders thanks to work from Collabora.