Is it affecting you? Do you have to pick up slack for this person, or are your departmental goals being hindered? If not, why do you care? I got someone fired

Is it affecting you? Do you have to pick up slack for this person, or are your departmental goals being hindered? If not, why do you care? I got someone fired once. He didn't do anything, the few things he would do he would mangle up, and he was seriously holding back departmental goals. The boss wanted to fire him but didn't have the nerve, so I helped him find the nerve. Immediately after, I took up a project he was in charge of and turned it into a real boon for the team, it built out the department basically and took it from being a liability to helping improve products substantially. It's a delicate thing though. Are you ruining someone's life? If they don't care enough should you care? Will coworkers stop trusting you? Does your boss care about it, and if not, will saying something blow up in your face? Is your product bullshit? Does your org have a culture of performing well, taking pride in it, encouragement and adequate compensation? Again, to reiterate, if it's got nothing to do with you, mind your own business, but if it affects you directly, then weigh the potential outcomes.