It’s acing standardized tests, building websites and hiring TaskRabbits — GPT-4 is “equal parts fascinating and terrifying.” OpenAI has released its latest model, alongside A.I. announcements from Meta, Google and other industry players. The A.I. arms race is only accelerating. Then, what Silicon Valley Bank’s collapse means for the future of start-ups, and what Mark Zuckerberg has learned about layoffs.