Group 1 - The trend of extreme work hours among AI startup CEOs in California reflects a revival of "grind culture" reminiscent of the late 1990s and early 2000s dot-com boom [2][4] - Young founders are motivated by the belief that the current market opportunity for AI will only last two to three years, prompting them to work intensely to build their businesses [3] - The "996" work culture, which involves working 12 hours a day for six days a week, has gained traction in the U.S. and is associated with the ethos promoted by influential figures like Elon Musk and Jack Ma [4][5] Group 2 - Many founders advocating for the 996 work culture are in their 20s, often without significant personal obligations, viewing long hours as essential for achieving success in a competitive market [5] - For a select group of workers in San Francisco's AI startups, a 72-hour work week is perceived as the only route to substantial financial rewards, contrasting with the views of older workers who may not share the same priorities [5]