I don't need to convince anyone of needing economists. Economists need to convince the world of their necessity and have never done so, nor could they ever. Human beings don't need economists to tell them how to live their lives and until economists come up with a good argument for their authority, no one ought to do anything other than listen to what they have to say and possibly give it some thought.
Remember, none of this has anything to do with you and your theories and whatever else you think has any bearing on the structure of societies. This is about general human necessity. People don't need economists or any other social scientists. The best we can do is be helpful participants and try to use our knowledge to help those who might lack it.
Now if you excuse me, I'm going to go out into the woods and try to kill animals with rocks and pray to the gods for fire.