Why isn't the fact that lots of baby boomers are getting older and retiring or getting close to retiring any part of this story? If bonds are the safer choice

Why isn't the fact that lots of baby boomers are getting older and retiring or getting close to retiring any part of this story? If bonds are the safer choice for retirement investments (compared to stocks, while cash makes no interest/dividends or gains in value, these are the only 3 choices), then clearly lots of older people who are retiring are going to be buying into bond funds. Hence, huge upswing in bonds held by ETFs and mutual funds, since that's mostly what working-class people have access to through their employers or in their other reduced tax retirement accounts.