Honestly both, and neither, depending on the framework you're using. But if we're talking in blunt terms, most people are neither saints nor monsters. We're just mediocre by design.
That said, if I had to pick a side, I'd say most people lean toward functional goodness. Not because they're virtuous, but because prosocial behavior is evolutionarily advantageous. Cooperation kept early humans alive. You didn't get very far as a selfish loner in a tribe based survival model. So yes, most people are "good" in the sense that they conform to the norms of their environment and avoid actions that would get them exiled, jailed, or rejected.
But if given power, anonymity, or desperation, that layer of decency can crack fast.