`with-current-directory` has to be a macro because if it is not, then the evaluation of (delete-all-files-recursively) happens before the definition of with-current-directory can change the current directory.

What the person meant when he wrote, "In those times I wish I could use the emacs lisp way," is, "In those times I wish I could use a lisp _macro_" -- particularly, one of those macros that makes a change, runs some code ("the body") then undoes the change.

Since all lisps have macros, the code above would work in any lisp -- not just Emacs Lisp. Among lisps, Emacs Lisp is famous for its dynamically scoped variables. Consequently, the specific reference to Emacs Lisp perpetuates the confusion that how variables are scoped has anything to do with what we have been talking about.

Yes, but emacs lisp is the only lisp I used, and lives in an environment where those macros are really useful.

    with-auto-compression-mode  with-case-table
    with-category-table         with-coding-priority
    with-current-buffer         with-decoded-time-value
    with-demoted-errors         with-electric-help
    with-help-window            with-local-quit
    with-no-warnings            with-output-to-string
    with-output-to-temp-buffer  with-selected-frame
    with-selected-window        with-silent-modifications
    with-syntax-table           with-temp-buffer
    with-temp-buffer-window     with-temp-file
    with-temp-message           with-timeout
    with-timeout-suspend        with-timeout-unsuspend
    with-wrapper-hook