I agree. My wife works for the federal government, and her agency fires people all the time.
Her agency has various metrics and performance goals that employees and the whole office are required to meet. The goals are not trivial, either. My wife is one of the best employees in the office, and she still finds the goals to be very challenging and high-pressure. When she was still learning the job, she had a great deal of difficulty meeting her numbers, which is apparently pretty typical.
Employees who fail to meet their numbers are put on a performance improvement plan (PIP). Those who don’t meet the requirements of the PIP are terminated. While there is a union and a review process for terminated employees, if the termination is due to performance issues, there’s very little that can or will be done.
Her office recently forced a guy to retire who had worked there for decades, but whose performance had supposedly declined in the last year or so.
They also have a fairly long two-year probation period in which it is even easier to fire a new employee. My wife sees a lot a new employees who apparently have the mistaken impression that federal service is a cushy job. They are quickly disabused of that notion. Those who don’t get the message quickly enough get fired. Of six new hires in the last year, only two are left, for example.