Looks like the goal of this project is to be a replacement for bash with improved interactivity. That seems reasonable, compared to what you can do with zsh or fish bash is far behind concerning interactivity.

While I personally think shells that abandon POSIX/bash compliance are much more interesting as those can implement a sane scripting language, sticking with bash but improving interactivity is probably going to make more users happy as bash is so ubiquitous.