I do not believe there are that many fully automated production lines and even those ... needs people to maintain them and build them and develope them and fix broken parts etc.
Believe it or not, its been happening. In fact if it isn't automated and is of any size, then it's been outsourced to Asia. When it grows to a sufficient size to warrant the fixed overhead of automation, it may return to the western world. But without the assembly-line jobs, giving lie to the idea that bringing factories back will create (many) jobs.
The 1% of 'old factory jobs' that are retained (Engineer, planner etc) won't employ many people.
I do not believe there are that many fully automated production lines and even those ... needs people to maintain them and build them and develope them and fix broken parts etc.