They're not richer than the entirety of Sony. But their products cost MUCH less to produce, be it hardware or software and it gets them more money compared to what they put into it. Hell, Nintendo will sell a 5 year old game for full price. Not to mention much smaller production values on their AAA games compared to other companies.They cant be richer than Sony. Pretty sure PS still has more revenue and profits than Nintendo
They just have an army of diahard fans that would jump off bridges if Nintendo asked them to, plus a lot of software aimed at kids.