Re: Exactly the problem that DLL hell causes.
You don't know what you're talking about.
DLL hell refers to the way windows used to insist on only one, correct, version of a library being used. You wanted to use 1.2 in one app and 1.1 in another? No way, the OS will only allow one to be installed.
That is dll hell.
What you're talking about is the exact opposite, the solution to dll hell, which is "each app keeps it's own dependencies, separate to every other app". One needs 1.1, it ships with 1.1, another needs 1.2 and ships with 1.2. This was marketed as "xcopy deploy" by MS and promoted as the solution to dll hell.
You're touting a solution that causes dll hell, shared dependencies.
The best solution I've seen so far is how pnpm handles it. That keeps a list of all dependencies and maps them into projects as virtual folders. So you can have four apps sharing a version of 1.1 and another couple of apps using a shared version of 1.2. No wasted disk space but you can still use multiple versions of the same library.