Arch with LXQT, maybe? Then you can choose to install specifically what you want with minimal overhead. Another option is the minimal version of NixOS, but like Arch, you’d need to install a DE separately, and you’d need to learn how to use Nix.
But if it’s still struggling, might be best as an art piece or command line only, given that a Raspberry Pi 4 and 5 can be had for <$100 and neither struggles with lighter DEs or browsers.