Is it true that men don't want someone who is brighter, more educated or knowledgable & has a higher income?

Your concerns and observations are true but like you rightly stated not every man or every woman fall into that category. Most people who fall into this category are very insecure or people who want to live their lives for others and by others standards. If you are comfortable with yourself, proud of who you are and have some sense of contentment, you should be able to marry any person you love and if compatible live with him/her. One of the purposes of real marriage is for the husband and wife to support each other emotionally and economically not seeing one another as richer or poorer but as life companions. A millionaire wife should be seen and appreciated as a wife and not as a millionaire and a doctor husband should be seen as a husband and not as a lawyer. What your wife or husband do if two of you are sincerely married to each other is the least thing in your mind when it comes to him or her.