if the businessman is interested in profit and his business depends on the bottom line, predicting business volume, and other fiat metrics, don't bother with investment angle - this inspires hopium & unreasonable expectations;

for a business that operates in fairness, bitcoin the mainchain is more valuable as an accounting system that cannot be hidden or fudged as is commonly done in shadow-banking; u can explain it as the triple-entry accounting, where accountants are the computers (nodes, miners); OP_RETURN can even be used for business notes, accessible by anyone anywhere; privacy implications can be addressed here as well;

another way it can be valuable for a fair business is longevity - a business that has figured out how to operate on bitcoin cannot be shut down; instances of censorship are rising in frequency & number;