On the other hand there will be a very large portion of society who will become obsolete with absolutely nothing useful for society to do.
A large portion of society that doesn't want to work on hot, dusty, dirty worksites might become obsolete with nothing useful for them to do. But there are absolutely jobs that are accessible to no-skill workers with only 1-2 years investment in schooling.
Almost everyone has something to contribute. The problem is that society structured in a way where most forms of productivity are undervalued. A great example of this is art. Nobody in their right mind could imagine a world without art yet there's the stereotype of a starving artist. Burger flipper robots aren't going to make or break the world.