The way I think about it is kind of like software versions. Say you want to do some kind of reproducible software. You can write that your software depends on jazzinator==3.0.0 but that's kind of unsatisfying because it relies either on tools or people to make sure that versions are immutable. It also relies on jazzinator to specify its own dependencies pretty strictly. So maybe you end up inventing the concept of a lockfile to partially solve that problem, but you still have the issue of relying on a third party to not change things up on you.

However, if you can address a library by a name that is computed from its code (a hash), things get interesting. You end up with this tree/DAG of dependencies where every dependency is immutable--you can't change the code without also changing the name. It's a Merkle DAG like Git. You do lose the ability to say things like "above version 2.5"... sort of.

If you also build a ref or tag system (similar to Git refs), you can kinda do normal style versioning on top of this content addressable world. But again, that relies on someone or something (maybe your hash-based store) to keep a map point-version names to hash names.

The other thing that's interesting with scrapscript in particular is since everything is addressable, you can use (sort of implicitly import/download) any value from any other program in a repository readable by you. But no scrapscript implementation fully does this yet, as far as I'm aware. For a fully working system, check out Unison.