the biggest (and hardest challenge of all times) will be in entertainment.
But entertainment is also something that can be trivially copied. A single movie can entertain billions of people. Furthermore entertainment also doesn't get used up, I can still get my entertainment from 50 year old episodes of Twilight Zone. So while I certainly do agree that entertainment is growing, I don't exactly see it as a solution, sooner or later there will be enough entertainment for everybody.
Entertainment is also not immune to automation. Games can already do a whole lot of things procedurally, what's to stop them from being flexible enough in 30 years to procedurally generate a movie or some futuristic VR experience? There is still a whole lot of work to be done before you can have procedural storytelling and acting, but we will be getting there.