Things get bad even before extractors enter the picture [0]; just a disadvantage in strategy update rate will result in the formation of cartel structures.
The economy will function as long as there are sufficient physical resources and human will. Finance cannot kill it.
For various definitions of human will. I think humans are somewhat fickle. Society might change its mind more easily than you expect. Case in point, Trump.
The economy will function as long as there are sufficient physical resources and human will. Finance cannot kill it.
[0] https://arxiv.org/abs/1201.3798