If you have to cd/ls around a lot, it's simply faster once you get used to it.

If your scripts do all of the following, you are already using a file manager:

https://github.com/jarun/nnn#features

That doesn't really help - something like "POSIX-compliant, follows Linux kernel coding style" doesn't really indicate what it's useful for.

My question isn't snark. It's more like "what is the usecase and what advantages does it have over standard terminal workflows?"

FWIW: My main file manipulations I need to do are within vim when working on a project. I typically use nerdtree for this, but having a project that's consistent in my environment would be good.

I do other manipulations using standard tools like ls/rm/etc. what advantages does this have over those ?

I answered to a similar question in the same thread (in response to the comment you replied to). Please take a look if that clarifies.

As a vim user, I got a good analogies, why don't you use vim over ex mode. The same applies here.