Conflict of interest has been a thing way before lawyers and HR types existed, they understood it and tried to prevent it at any point in history, from ancient Babylon to Rome, and from Amazon native tribes to imperial China.

It's of course also the explicitly expressed reasoning for why there are independent branches of government (legislative, executive, and judicial in the US).

>I'm an optimistic engineer, believe in win-win situations, and don't see everything as a conflict.

Yes, it's called naivety :)

Civilization is already an unnatural situation, in the sense that we have to coexist in groups (and with other groups) bigger than Dunbar's number.