I think the issue is not that there are missing features, it is that there are too many features. Elisp would benefit a lot from pruning and standardization of its many, many, many builtins.
This is a very hard problem to recover from, because backwards compatibility is so important for something like Emacs. Breaking old versions would be completely unacceptable, which makes it very difficult to remove any features.
This is a very hard problem to recover from, because backwards compatibility is so important for something like Emacs. Breaking old versions would be completely unacceptable, which makes it very difficult to remove any features.