alt Hacker NewsThere are millions of jobs that can be fully automated with 20th century technology but are still done by humans today because 1) third world labor is just too cheap 2) unions and other job protection policies.
Therefore the scenario where 'all jobs being replaced in a short time span' is simply impossible.
Sometimes that delays it.
But when the tech is good enough and cheap enough then the picketing unions find their only barganing chip, that of witholding their labor, has become a toothless threat: no matter how long and hard a person of the profession "computer"* refuses to work for me for daring to have an unauthorised "electronic brain"**, the absense of that labour will not cause me any loss.
* https://en.wikipedia.org/wiki/Computer_(occupation)
** https://archive.org/details/electronicbrainh00cook/mode/1up