Zero sum thinking is destructive - if the only way I get ahead is by taking from you, then I want to take from you, and I regard anyone else's success as proof they took from me and justification for violent "redistribution".

This is the core issue with Marxism - labor theory of value creates zero-sum thinking. If values are reducible to a single value scale then all exchanges are more for less (exploitative) or equal for equal (pointless). Thus Marxists can't explain trade or cooperation.

The theory which eclipsed the classical/Marxists labor theory of value is subjective value. I value different things based on the use I can put them to, and so do you. I might value A above B and you might value B above A - and we can both be right! Therefore, voluntary exchange is mutually beneficial, neither exploitation nor pointless shuffling.