In some cases eshell it's far better than sh, altough anything can be better than POSIX sh. Just try rc under 9front (or, as a demo, under GNU/Linux or OpenBSD). GNU tried to create a better interface to Unix with Emacs (and it shows) and 9front just went further throwing down all the legacy crap to the dust bin creating something better. No X, no ioctls, no sh, no Perl, no C++ (golang works, same people in the end).
I think Emacs today with the jitted Elisp interpreter it's able to do far more stuff than depending on external tools such as GNU coreutils, findutils and non-GNU Gnuplot. The 90% of these could be rewritten and even expanded and enhanced under Elisp running pretty fast and interfacing much better with Elisp than any other tool.
Ironically GNU on-current-unixes (and outside of Hurd) it's holding GNU and Emacs back, because a nonroot user can do far more stuff (without group permissions) under Hurd than in GNU/Linux. Think something like namespaces, remote mounting devices a la Rclone (and not just drives) and so on with a boosted Elisp interface and org-mode to manage far more stuff under you account than these restricted Unixen. But a paradigm change is needed.
The 9front users already got it, and the GNU Guix people just began doing that under Guile. Who knows, maybe in 15 years Emacs it's rewritten fully under a uber fast Guile with libre RISC-V microcode based CPU's from Taiwan or Estonia or whatever, loading Guile-optimized code on demand for HPC tasks and the like and some others loading a server-balanced microcode (and OS settings) grom a custom Guix config. That would yield a very different computing than the one we are suffering today. It would be the second Golden Age, similar to PDP10+ITS/WAIS creating the path for the literal 60 years of computing where basically Lisp and Forth invented everything or nearly everything.