> please tell me how these companies that are being invested in in the AI space are going to make returns on the money invested? What’s the business plan?

Not a VC, but I'd assume in this case the investors are not investing in a plausible biz plan, but in a group of top talent, especially given how early stage the company is at. The $5B valuation is really the valuation of the elite team in a arguably hyped market.