Michael Cannon-Brookes became a billionaire in his 30s and one of Australia’s richest tech executives with the initial public offering of software-as-a-service firm Atlassian Corp. just over a decade ago.Now, along with co-founder Scott Farquhar, he’s at the sharp end of a global rout in stocks that are seen as threatened by artificial intelligence. Together, the pair have lost about $7.2 billion this year, or a third of their wealth, turning them into the biggest billionaire losers in software ...