Germany was the first whole nation, in 1918, to use Daylight Saving Time to reduce energy consumption. Many other nations adopted it around the same time, including the USA, but then phased it out. DST returned in WWII. After WWII, DST was a local option, which created time-zone chaos. In 1966, Congress passed the Uniform Time Act, requiring that whole States either participate in DST or not. Arizona opted out. DST succeeded at the original goal for a while, but now this time change either does not save energy, and possibly even increases consumption.
It's also just a giant pain in the butt and increases stress for millions. Other than a reminder to change the batteries in a smoke detector, there is no logical reason to continue this tradition. End it already!