Automation can only help social security. The fix would only fall short if the yield curve for automation falls behind the yield curve for the productivity provided by human labor (possibly from declining birth rates).
Where would the extra dollars come from less humans? Monetary Policy: 20 years ago, the starting salary of an engineer hovered a little over 35k. Now, it appears it's around 90k.Less humans making larger salaries, paying higher ratio of FICA taxes.
Ultimately, this is about the ability to provide goods/services to a larger population *not producing it. We can financially engineer a way that SS retirees are paid whichever amount, but without the current facilities to render goods/services behind that US $, the money will ultimately be useless.
OT: there's no need for the concept of taxing automation (whether software or hardware) in Social Security discussions. Automation is actually a business expenditure and not a taxable entity. Rather, it would reduce the taxes an entity like a corporation would pay in the process to provide said goods/services. ie. you wouldn't tax the robotic welding arm in an auto factory that replaced 2 welders making 50k; but impose FICA on the human inspector of those welds with a 100k salary.