What's wrong with dired mode? Ok, you'll get each directory in its own buffer. But, thinking of that, it shouldn't be to hard to make dired mode recurse into subdirectories inside the same buffer. (And fold/unfold like orgmode does. ;-)

It's a single variable setting now:

https://www.manueluberti.eu/emacs/2021/07/14/dired/

dired-subtree does this, albeit on demand, not eagerly descending into subdirectories. dired-hacks more generally has lots of good stuff like filtering etc.

There's a broot alternative called lf that opens files in $EDITOR

https://github.com/gokcehan/lf

What would be nice about that?

You could edit files that you just found and renamed. And when you edit files, then there is RCS integration and… linting, spellcheck, printing, you name it. It’s just a unix way. Is broot ISO/IEC 9945:2009 compliant?

/s

That it would contain emacs