Question: What will all of the people do post-automation?

This is the crux of my ramblings and questions:

"If trends continue, within 30-50 years (maybe sooner), 1/3 of the global jobs will be replaced by automation (AI robotics, etc), and simply less global consumption...and the population will be >10B people.  What will all of the unemployed and underemployed people be doing?"  I hear that we have roughly 2 generations before this really happens (because in the interim, we need people to rebuild infrastructure and the actual tools of automation).

Here are some articles for context:

• https://qz.com/904285/the-optimists-guide-to-the-robot-apocalypse/
• https://www.wired.com/brandlab/2015/04/rise-machines-future-lots-robots-jobs-humans/
• https://qz.com/940977/no-one-is-prepared-to-stop-the-robot-onslaught-so-what-will-we-do-when-it-arrives/

Personally, I am a pessimist, so see mostly the downsides (for the mass of humanity and society).  I just don't believe that the low-skill service/labor jobs will be replaced by other jobs.  There are simply too many uneducated, poorly trained humans.

If we continue our current path, I see only a few futures in which the mass of humanity can live fulfilling lives (this is a very a low bar, since so many already live in scarcity and insecurity...think Africa, Asia, South America, etc.):

1. Less population.  This solves the problem because we'll NEED robots to help run the world.  I can imagine a few scenarios here. There are a few options here:
• A Great war or wars.  Barring a global nuclear war, I find this scenario unlikely because war is increasingly automated and does not actually kill that many people.   Let's hope it's not nuclear.  In the meantime, I don't see other wars affecting population significantly
• Pestilence/plague.  I see this as more likely.  With the rise of antibiotic resistant diseases and more human density, this might keep the population down.  Again, let's hope not.  For the record, the Black Plague, wiped out 25-30% or population.  So the scale is possible.  The question is whether any specific disease can spread fast enough to affect this many people before we humans find a solution.  I don't bet against humans here.
• Governmental action.  The government can start to enforce fertility rules.  This is extreme, but perhaps not unfathomable.
• Natural drop in fertility/birthrate.  Perhaps children just won't be as popular.  Wealthy countries consistently see falling fertility rates due to many reasons (economic mainly, but also because each child has a higher chance of surviving to adulthood and reproducing, so there's not so much need to make so many).  China and India are already tapering off...so that's a positive sign
2. A world of walled cities.  Where the haves are separated from the have-nots.  Not much to add here...just image Robocop on steroids.   Militarization of cities mainly protecting the elites, "Soma-for-all" to pacify the masses.
3. We escape outside of the Earth to colonize the stars en masse.  This would require lots of humans...so in the extremely unlikely event that this becomes possible in the next 50 years, it would be great

I understand that this is a Hobson's choice, that not all the possible outcomes/choices are listed, but these are the "obvious and logical" outcomes that spring into my uncreative mind.

The reason I'm writing this is NOT because I'm hopeless, but I feel that we collectively need to start now to envision a collective positive (practical) future, and start working toward achieving it now.    And to do that, we need more ideas/solutions that can make an impact at a a large scale.  Bill Gates, Elon Musk and other visionaries are doing this...but I still feel like their efforts are out of my reach to participate/contribute.  I hate to think that our futures are resting on a few smart people on the West Coast with the rest of us just waiting to see what happens.

What are other likely/probably outcomes you envision?  Please comment below!