Why think about this as #underwork not underemployment? Because underworking is a human condition with human impact, like overworking. Underwork is a social situation.
And unless the sparkly new futurey jobs show up, AI driven underworking will expand the demographic of an established and generationally impactful underworking class: working under the level of wealth creation, working insecurely, with fewer protections, weaker access to fair work provisions, solidarity or safe protest.
These are long term political choices.