An investment that needs to return 7x, alone, on hundreds of billions to trillions of investments... While not destroying the entire economy, or replacing it?

If you can capture a significant fraction of the gains made by automating lots of white-collar work, then those billions/trillions look more reasonable.

"Correct" investment volume towards early industrialization might have looked just as unreasonable without the benefit of hindsight.

How exactly is capturing 75% of white collar work not collapse western capitalism?