You are on a team and that team has at least one member that isn't pulling their weight. The reasons why generally range from a lack of work ethic to a lack of talent.

I think they are pushing the incompetence angle too hard in a way that the author seems to be trying to elevate himself at the expense of others.

If your team hired and retained a guy, that means that team member passed the hiring bar you passed and justified his place in the organization. It's highly unlikely he started to underperform because he unlearned stuff or suddenly became incompetent. Odds are you're dealing with a team member that is experiencing mental health issues such as burning out.

If that's the case, the mere thought that a team member decided to devote his time writing up articles on how to stab team members in the back when they're at a low point of their life reeks of a toxic work environment.