Personally, I don't like this kind of thinking that it's a failure of leadership first and foremost. Yes, of course leadership can both work proactively to prevent conflict, as well as try to minimize/react to situations. But, what about the conflicting people? Shouldn't they (in most situations), bear the most responsibility to not end up/turn a situation into a conflict? Sometimes I get afraid of comments that (in my interpretation) imply that basically everything bad that happens is the fault of leadership (management). To me that breeds a culture where ICs are taught to not own their situation, which I believe is very very dangerous (to everyone involved).
As an IC leadership picks my coworkers and my projects for me. Why should I be made responsible for the consequences of their decisions? What do you think leadership does do if not build successful teams? If I am expected to get along with everyone on my team then I expect to be allowed to make hiring, firing, and prioritization decisions. At which point I’m now leadership and we don’t need dedicated leaders.
Maybe I'm just interpreting your comment wrong :)