Amazon founder Jeff Bezos recently invested in a robotics startup — and he's not the only billionaire putting money into the sector. Bezos has invested in Physical Intelligence, which is working on software that'd allow robots to perform tasks like folding laundry, bagging groceries, and clearing tables. The startup announced earlier this month it has raised $400 million in early-stage funding from Bezos, OpenAI, and VC firms Thrive Capital and Lux Capital at a valuation of more than $2 billion. Elon Musk has been working on the Optimus humanoid robot for years.