Building a super yacht means that dozens or hundreds of people work for the benefit of one person. As craftsmen, they could have improved the lives of tens of thousands in their community instead. As engineers, they could have built products serving millions.

Not to mention the natural resources used for one person's benefit.

There's nothing positive about super yachts (and mansions, private jets,...) being built. Don't let the flow of money confuse you.

This is actually an example in The Wealth of Nations; Adam Smith considers whether a hooligan smashing a window is a benefit to society because it creates work for the glazier.

Smith concluded that no, it isn't a net benefit because the glazier could have made a new window instead.

However, given that megayachts are net negative to society, I'm not sure how he'd view this case.

Money goes from the billionaires to the millionaires that owns the yacht companies 😅

The argument is sloppy.

The working class makes gains when our work helps us as a class, not when we are forced to serve.

If the wealthy are able to support the creation of wasteful luxuries for their own vanity, then they must be able to support activities that help the working class.

The difference is that the latter may require some encouragement.