So why are shell languages still around? Why are they not replaced by C#, C++, Java or another big (=general purpose) language?
I find your horse->car comparison more akin to the sh->bash->zsh transition. Zsh is not as small as sh, but still it is in the small league is you ask me.
Small does not mean w/o functions, without NS, without map/filter: it means "not general purpose".