Earlier quoted context omitted.
It's not totally true even for knees. Artificial replacement knees aren't as good as original knees.
I’d argue they’re better (in some ways), given that they’re “dead” material as opposed to functional tissue. Human knees don’t last nearly as long when the tissue is dead.
If you're active, knee implants have to be replaced after 15-20 years, because they detach from the bone. Knee implants can harbor pockets of infections because they don't have an immune system. They are also more prone to dislocations.
They are objectively inferior to a healthy organic knee.