When I work together with people on projects, I make them to agree that nobody other than the author of commits is allowed to resolve merge conflicts, and conflicts must be resolved in the feature/pr branch that is going to be merged into the main branch(es)

I would agree that _most_ are easy. But the upper bound for difficulty to understand is quite high. And even if they are easy when both authors work together it'd be even better to _not_ spend two people's time on that. So why adopt a workflow that's guaranteed to maximize merge conflicts?