I had a quick idea today.
Basically, it'd work similarly to npm, but for Minetest. You could install mods, subgames, texture packs, utilities and maybe maps with it. It could work directly using Git or from archives. It could be made to handle dependencies automatically, too.
You could invoke it from a terminal using a command like mpm (with subcommands help, search, install, update, remove, …).
For this to work well, modders, subgame developers and texture pack developers might have to add a package.json file which would contain version information and other metadata.