"Pull one's weight", or in some cases, "do one's share" is a relatively informal and common expression. It's perfectly natural in a casual conversation about the relative efforts of various members of a team, who work together on a common task.
It can be used as a "buzzword" (or "buzzphrase", I suppose) when talking about an employee's individual effort. An office working environment requires some measure of teamwork, so even if an employee works primarily on isolated tasks, their effort contributes to everyone's overall success.
I don't know if it is a cultural thing to have managers in a company who don't like to criticize employees directly. It's common in the United States where a disgruntled employee can sue for wrongful termination (or, sometimes, do worse things). In such cases, for example, a manager might say something like
He's not a team player
when the manager really means
No one on the team liked him very much.
In the formal context of something like a performance review a manager might tell an employee that they aren't "pulling their weight" as a way to suggest that their unsatisfactory performance pulls down the entire team, as a way to motivate them to work harder.
In a formal context, it's fine to say something like
The employee had consistently unsatisfactory job performance
The employee consistently did not meet performance expectations
The employee consistently underperformed in their duties
as well as many, many other variations, all of which are various nice ways to say they weren't very good at their job.