Fish is amazing as an interactive shell. I've had it as my default for a couple years now. Oil isn't the only game in town for object shells, there is also NuShell and Elvish which follow the fish model of abandoning POSIX compatibility for ease of use. I think OP had mentioned it elsewhere on this thread, but I've found object shells mostly useful for scripting that involves a lot of calling and processing the output of programs that produce structured data. I mostly use PowerShell for this, though Nushell/Elvish/Oil seem to be actually usable now. I'm pretty excited that the Unix community seems to finally be moving on from defending the old unstructured text model of program interaction to embracing the benefits of object shells. Whatever you think of its implementation, PowerShell is a great idea.