Does a billionaire business owner need a huge personal yacht as business asset for the business to serve the public?

Mark Zuckerberg's 300 million dollar yacht is an example of wealth that I think should be taxed more. I can see a billionaire business owner needs to keep the wealth that runs the business, like server farms for instance, but a huge yacht for personal private use? Maybe he needs it to entertain for recruiting top talent to the company? That's all I can think of for it's possible justification. Somewhere, a line does need to be drawn.