Traditional shell completions are quite difficult to make. Many CLI tools have completions for subcommands and options, but not for arguments. Only the big CLI tools like `git` and `docker` have arguments completions (e.g. git push [remote] [branch]`.

Fig's declarative schema makes building the completions for subcommands, options and arguments very easy. This means we can support much more powerful autocomplete for many more CLIs.

Fig's standard format also makes it possible to suggest shortcuts for standard workflows (similar to aliases but more visual).

Finally, zsh and fish have good support for traditional autocomplete, but bash does not. Fig works the same across all shells (even when in an SSH session or a docker container).