[int_19h]

In the current arrangement, capital by itself is useless - you need workers to utilize it to generate wealth. Owners of capital can then collect economic rent from that generated wealth, but they have to leave enough for the workers to sustain themselves. This is an unfair arrangement, obviously; but at least the workers get something out of it, so it can be fairly stable.

In the hypothetical fully-automated future, there's no need for workers anymore; automated capital can generate wealth directly, and its owners can trade the output between each other to fully satisfy all their needs. The only reason to give anything to the 99.99% at that point would be to keep them content enough to prevent a revolution, and that's less than you need to pay people to actually come and work for you.