So, now we'll be constantly fighting each other with endlessly evolving AIs. The world is already a cuthroat place with fierce competition.
Think of this analogy: imagine a karate match with people fighting each other. Sure, some people will get hurt but it's mostly controlled. Now imagine a world of people fighting each other by flying airplanes into each other...everyone dies.
We are unprepared for a new world where thousands of people fight for their slice of the pie with advanced AI, and it will either result in insanity or else a hugely more efficient use of resources (the FIRST thing people will do is find out how to use advanced AI to get a bigger slice of the pie) so that the natural biosphere will be even more efficiently destroyed.