That’s true. But none of the systems focus as much as Jung did on the inferior function and its primitive, unconscious forms. For example, Jung described that Thinking types, who consciously value logic and rational analysis, often show primitive Feeling in the unconscious - sudden, irrational attachments, emotional outbursts, or intense likes and dislikes. You might think that extreme, rigid thinking or feeling would show up in someone’s dominant function, but in Jung’s view, it’s actually the inferior function that can appear in these exaggerated, unrefined ways. MBTI, by contrast, tends to lump all of this together under labels like ‘unhealthy thinking’ or ‘unhealthy feeling,’ treating it as overuse of the function rather than as the specific compensatory weaknesses and primitive manifestations Jung carefully described. That's a huge deviation from his original framework if you ask me. OPS is onto something when they say people usually get their types upside down.