I get on well with a big cross-section of people, part of my job is to smooth over the gaps between clashing personalities (IRL, online I'm an argumentative bitch)

Anywho, there was one guy who I just couldn't work with - he blamed anyone but himself for his mistakes, and he kept on repeating them. He was also intensely lazy, and called off during covid for a total of about 6 weeks. Then, every time someone tried to help him improve, he'd file a complaint of harassment against them - at separate times against me, my boss, and every single other person he worked with.

He raised a complaint with our union (which I'm still a member of, since I'm just a supervisor) saying there was systemic harassment. It took over a year to fire him.

The moment he went, productivity went up, and has stayed up :-)