We are now a global world.
The act of changing time twice a year causes disruption to numerous business that work with other countries and need to readjust their work schedules/practices to realign with the new time.
This cause problems for those who work shift work. When can they go home and when do they need to come to work with those shifts that straddle the time change hour.
This change in time also disrupts sleep schedule. People in critical jobs such as air traffic control are often tired for days to weeks until their bodies adjust to the new time.
With today's technology and business' it doesn't make sense to continue with an archaic practice of shifting time.