4) Add new jobs to do new things.
5) Do more complex things - automate the boring bits and use people to do the creative bits.
There's no reason why the total amount of work output by the human race should remain constant. So I dispute that more automation of jobs inevitably leads to less work for people to do overall.
To answer this seriously:
What jobs are going to replace the ones that are being automated? If you buy a robot to replace one man, you need to pick from one of options 1-5. If your argument is that we'll just find a new or more creative job for him, fine. But another reason for buying a robot is to replace many men. Now you have to find something for many men to do.
I don't doubt the ideal of finding new and more better thinky-time work for displaced box stackers is a laudable goal, but it isn't always practical, and it has never fully worked.