They never really caught on big in the first place.
That's what I thought to when I saw this topic. Here in the USA I've only seen a few guys performing in public arrangers with auto accompaniment. Just from my observations from the last few years, when I hear solo or duo, they are playing live without tracks or drum machines. Usually guitar players, sometimes with a loop pedal. The acoustic, organic," unplugged" sound seems to be what general expectation is for a solo/duo act.