> Shells often use this knowledge so that names like '..' and even '.' work on the text version, not the filesystem version.

Which has the odd result that '..' behaves differently between shell builtins and normal commands. `cd ..; ls` uses the text version, but `ls ..` uses the filesystem version. `cat < ../x` uses the text version, but `cat ../x` uses the filesystem version.

I like the text behavior in theory, but this inconsistency is weird enough that I question the benefit of having the text behavior at all.