Now it is the nature of every man to pursue good and avoid
evil, and to regard that man as an enemy and betrayer who deprives him of the former and involves him in the latter, even though he be a brother or a father or a son. For nothing is more closely related to us than the good. It follows that if good and evil lie in externals, there is no affection between father and son, brother and brother, and all the world is everywhere is full of enemies, betrayers, and informers. [ Discourses IV. 5. 30-31 ]
Nothing of the sort follows, Epictetus, and you know it.
If some externals are both good and things for which we compete, sometimes unjustly, then there will be conflict, which we must learn to manage. And if some externals are evils, then we must study to avoid them, and again, there will sometimes be conflict, which we must also manage. But " all the world is everywhere full of enemies" is a symptom of paranoid delusion, not an inference. Epictetus is trying once again to sell us a false dichotomy: either turn your back completely on material, external thing, or prepare to live in constant perpetual conflict with evryone else.
But if a right choice is the only good and a wrong choice the
only evil, what room is there for quarreling or reviling? About what? About something thar is nothing to us? [ ibid]
Right choice and right desire and right belief are vital goods, but do we believe that they are the only goods? Aren't some externals like health & a decent standard of living indispensible for living a life worth living? Health and fitness are not things for which we compete. You may be as healthy & fit as you wish and so may I. Arguably, my having a decent standard of living also does not mean I must oppress and exploit you. Some other external goods are competitive and so we must compete, at least for our fair share. So be it. But let us not pretend that pursuing any externals is recipe for unceasing, implacable conflict with everyone.
[ I follow Robin Hard's translation in the passages above. ]