For how many thousands of years did innovation only increase the employment of horses? Until suddenly their employment suddenly dropped, and hasn't increased in a century.

Your analogy only works if people are horses. If you could employ a horse as an office manager, you might have something.

Compared to future AI we may be horses. Or even just comparing those who can automate to those who cannot.

Regardless time will tell

The number of people working in agriculture has shrunk significantly.