A Genuine question about caring for patients with complex chronic Illnesses

I am a medical intern, and I have a genuine question for more experienced physicians.
Why do so many doctors seem to believe that patients with conditions such as POTS, ME/CFS, fibromyalgia, Ehlers-Danlos syndrome, and MCAS are exaggerating, seeking attention, or even fabricating their symptoms?

I understand that these conditions are complex, their symptoms are often subjective, and overdiagnosis and misinformation can make these consultations challenging.

As a future physician, I would like to know how you approach these patients in daily practice. How do you balance healthy clinical skepticism with empathy? How do you distinguish a genuine case from another diagnosis, psychological factors, or, in rare situations, symptom exaggeration or factitious behavior?

I would really appreciate hearing how experienced clinicians navigate these consultations while ensuring patients feel heard and receive appropriate, evidence-based care.