I had to say it again today. If somebody is not performing, most often, they need the system of work fixed so they can actually get their job done, and the ways of management changed to allow that. Training in a crap system doesn’t help.
Sometimes they need a different role within the system that makes better use of their potential.
Or a better manager.
Occasionally it’s lack of training.
Most rarely, it’s incompetence, which reflects badly on HR and the hiring manager.
There is way too much “shoot them” management machismo.