Sam Altman sold a company before most people enter professional life, so while I agree with him that equity and ownership is the best way to extreme wealth, I think he should probably acknowledge the TONS of people making great money who are quite wealthy on a salary basis as well. Discounting that as a "young man's misunderstanding" seems... weird.
Well it depends what you mean by "TONS" of people, or "great money", but I don't think you're right. Most people on a salary don't make enough money to be considered rich, IMO.