Diversification is more appropriate for an investor than for an entrepreneur. For an entrepreneur, it’s important not to spread themselves too thin with excessive diversification. This is if the entrepreneur is a producer of something. If, however, the entrepreneur’s business is trading, then yes, expansion makes sense for them. By the way, a single asset can quite make an investor rich. For example, this happened with early investors in Bitcoin.
I feel this part you said “Diversification is more appropriate for an investor than for an entrepreneur “ is not actually correct man, in my opinion, diversification or expansion as an entrepreneur or a business person is very very possible, regardless of the business.
It depends on how sound the individual or the entrepreneur is, a solid entrepreneur can start a business, and simply build a structure around it that would sustain and make the business run without his or her presence.
Then he/she could decide to diversify into another similar aspect of that business or something entirely different, why that previous one still runs perfectly well.
In as much as a single asset can make an investor rich, a success business can as well make an entrepreneur not just rich but wealthy.