If you have a Traditional IRA or 401(k), you are required by tax rule to start taking required minimum distributions (most of the major brokerages have tools to help you manage this) by April 1st of the year after you turn 70 1/2. One of lesser known benefits of a Roth IRA is that there is so such similar requirement to take required minimum distributions. You are in total control when it comes to RMDs and Roth IRAs.
Granted, you can begin taking distributions at 59 1/2 on 401(k)s, so by the time you reach 70 1/2 you may need those distributions. However, it’s always nice to know that you can take out your funds on your terms, especially since the government won’t have let you touch it without penalty (outside some generally negative situations, first home excluded).