Billionaire investor Mark Cuban.John Lamparski/Getty Images In a June conversation, Mark Cuban called out the No. 1 time waster in the office. Cuban says he will only take meetings and phone calls if there's "no other way." Earlier in his career, Cuban would run standing-only meetings to ensure they ended faster. If you're a believer that most work meetings could be condensed into emails, you're in very wealthy company.Billionaire investor Mark Cuban called out meetings and phone calls during a June conversation with author Chris Voss on the streaming platform Fireside.