You’re describing a weapon, and if AI managed to do that (I believe we are not far away), then this would probably increase the investment not decrease it.
Would it? I don't think so. Not if the weapon is an indiscriminate one and makes everyone worse off. Yes, some people (maybe military generals) might support it. But there would be near universal hatred for it, if people wake up one day and find their bank accounts not working or their eletricity not working.
This is why I think AI is so stupid. It's just too powerful for anyone to control, especially with the inertial mass of capitalistic society powering it through the incremental, short-term advantages it gives.
It would at least increase the caution and regulation around AI, which would be beneficial.