You don't hear this term used as much as you used to. According to the book [["Quiet" by Susan Cain]] it entered the public consciousness in the [[1930s]]. I feel like people use the term narcissist instead these days. That's the default psychiatric insult term to through about by people who doesn't understand what they mean.
Though according to GPT-4o they are different. Very different in fact. Narcissism gives people an inflated sense of self worth. And a inferiority complex is the opposite.
![["Quiet" by Susan Cain#Inferiority Complex]]