Personally, I hate competitiveness to the degree that I'm not good at competing, I just can't win, it always tell me a loser no matter what which cause bad and harmful feelings. In competitive gaming, I'll lose while most of the time I'm way better than the opponents and with more skills and understanding. So on paper, I should be a top player but in reality, I'm nothing but a "loser". So fuck competitiveness, while winning can trigger brain reward system but many times opponents will get hurt or not like losing. So its bullshit either way
Cooperation, on the other hand, while glorified and its actually theoretically good but practically it becomes bullshit. Look at co-op games and specially board games and how one can compete for leadership and everyone wants to enforce his ideas on others and will flame anyone who will cause a lose. Its something like capitalism vs communism, no matter what they say in theory, both are shit in practice because many humans are toxic no matter what, its just that competitiveness encourage more toxic behavior which is clearly can be seen in sports like provoking the opponent and tactical fouls and even in clean play, passive aggressiveness can happen and dirty tactics can be applied.