Libxo is neat, in theory, but it seems like applications are left to implement their own logic for a given output format rather than being able to pass a structure to libxo and let it do the formatting.
I can't remember the exact utility--I think it was iostat--would use string interpolation to format output lines in JSON and combined with certains flags produced completely mangled output. Not sure if things have improved but I would have expected something like JSON lines when interval is provided.
Powershell and kubectl are miles ahead of libxo in useability imo