Sure, but only because it's legal tender and people receive salaries in bolivars. They need to immediately get rid of their bolivars to retain any value. Venezuela and countries in similar situations have also demonetized their currencies, taking large notes of circulation on short notice. This screws over currency holders really bad.

Whether a currency still exists or is used at all isn't the goal post. People generally want to hold reserve currencies, currencies that are widely accepted and reliably hold value.

The USD isn't going anywhere. The DXY is trading where it was in the late 1980s. It's comfortably above the 2008-2014 trading range. But any time a recession or short time financial crisis hits, you can be sure people will be calling for the dollar's collapse.