Because Steam is drm, i would work only for some games somewhere would be some list.. with Gog games are would be much bigger success rate, but rebooting or building some own Digital to XP library is hassle in comparision with working client, i made such thing for DOS and Win98, you need same thing for console emulators.. but do same thing for XP is annoying time consuming,, not possible for every game (Steam there is not Steam for XP, so there where only some back in era DRMs and games are usually working with virtual cd images) and you need much more storage space.

It seems to be similar hassle like to using physical cds and dvds, what is prehistory.

Steamlite = SteamCMD, i havent time to investigate it, but doubt that its multi-threaded i way that you can schedule more downloads in queue and prioritize them and change order etc.. and you need somewhere to print some steam AppID etc, its not ideal.