Once real AI comes I'm not really sure what will happen because it is unpredictable how the AI will be made, but if the past is any indication it will be made recklessly in a race between a bunch of companies. Idk how long our current world order will continue to exist and how much the AI works with us after that event. Hopefully the zoo it keeps us in will be nicer than the way we have treated animals, and hopefully that takes 20 years after the birth of real AI.
I wouldn't worry about innovation slowing down, I would worry about the end of meaningful human innovation that we are clearly headed towards.
some possible areas - AI, 3d printing, falling renewable energy prices, continued marginal gains from computers, quantum network communication, longer term - quantum computers, expansion of VR, driverless cars, etc. Point being there are a lot of promising areas on the horizon.
It seems that we're currently approaching the top of the S-curve for computation via integrated circuits; further increases going forward are likely to be incremental and margin-focused, as opposed to paradigm-shattering. Maintaining the 1950-2010 rate of productivity improvement will require new paradigm-shattering advances in some other field (machine learning? Internet of Things stuff?). It's possible that these are indeed forthcoming, and we can continue our absurd growth levels for another fifty years. It's also possible that we're nearing the edge of the problem space and we won't have any more easy order-of-magnitude productivity boosts. If the latter is true, then our economy will inevitably collapse with enormous collateral damage. As an economic system, this seems unstable at best.