Eek. "No one has success with 1 product".
Everyone who is successful, has had success with 1 product..
Amazon *is* one product. The product is not what it sells, it's the online store that allows people to easily get access to other products.
Starbucks have more than one product he said? What?

They sell coffee. If they stopped their coffee no one would go in there for cake/sandwiches.
Walmart sell 1 product. They sell convenience. Their product is walmart superstores. Take that away and they're out of business. Turn it into something else, selling the same things they sell, and they're out of business.
If you look at almost every multi millionaire, you can trace 80% of their success to one single product. One single thing.
Focusing on 1 single thing is how you succeed.
Grant Cardone also makes the bulk of his money by focusing on 1 thing. Being a social media high energy you can conquer the world guy.
I would say there's a lot of spun crap in his story.
He keeps talking about how he's going to be a billionaire. It's pure hype to get people worked up.
If he really was making the bulk of his money from real estate he wouldn't be spending so much time making videos for the general public. He would be focused in private on becoming a billionaire.