We remember people who are the face of things that change the world; inventors/discoverer/scientist/etc. (Edit: it sounds like you're ...) Implying he's a businessman so will not be remembered makes no sense. If Musk colonizes Mars, he will be remembered. Social media may be a footnote in history, or it may be looked back on like the industrial revolution except there is no single frontman for the industrial revolution. Zuck has inspired an Oscar winning movie and now Congressional hearings, so I'm pretty sure he's the face of social media and history will basically be written that he invented it; although we know that's not entirely accurate.

Can you name the person who invented the printing press? The person who invented the cotton gin?

Jakob Fugger the Younger, the most wildly successful link in the Fugger dynasty of bankers to the Habsburgs, and who was immortalised in the 1990s German video game Die Fugger!

Crassus was one of the three triumvirs with Pompey and Caesar, but was formerly better known as a a famously unscrupulous and fabulously wealthy business man.

Perhaps most notoriously, he invented a fire department that would only put out your house fire if you sold the property at the price he wanted. Negotiations went on as the house burned.

The nature of business is so different today that direct comparisons are difficult but you might call Crassus a businessman

Not quite that early but Isambard Kingdom Brunel is pretty memorable.

Columbus himself was arguably a businessman.

Seneca the Younger