Updated 14-Sep-2023
At first glance, Fig seems to be re-inventing the wheel when it comes to autocomplete, but it is actually doing this at the OS level, and not integrating into the shell. Linux is not yet supported (10 April 2022), but coming soon. This means a faster implementation of extending the shell. Bash-it is the great framework for Bash, but it does have a learning curve (as does Fig). The biggest issue is, if one already has customizations of .bashrc and/or .bash_profile, then one has to re-implement this in Bash-it, as otherwise it overwrites customizations with its own.