Day Light Saving comes with many assumptions; the key one is that it saves energy, and therefore money.
In summer, when days are long, why not go home and enjoy your lives under the bright sun: catch a short round of golf after work or walk in the park after dinner. Save energy by not turning on lights for a couple of hours. That’s very nice.
It works only for regions of certain latitudes. Daylight change very little near the equator. In polar regions, the summer days are so long that it does not matter. In both cases, daylight saving time has little, and sometime negative, effect on energy consumption.
The shifting of clock comes with some undesirable effects. People turn on air-conditioning or other cooling devices when they arrive home. If they stay outdoor, they increase the risk of getting skin cancer. Activities start at dawn will deal with darkness.
Global coordinating are bothersome since regions are inconsistent. China and the state of Arizona, for example, do not observe daylight saving at all. Most European countries do it 3 weeks later than the US. Airlines, meetings, computer software, TV schedules, etc. all must tolerate several weeks of confusion.
Record keeping is a problem too. If an event happened at 4pm 5 years ago, how many hours it has been since? Astronologists will have trouble telling your future if your birth time is off. Do you know what time will it be 30,000 hours from now? You cannot. The regional government may change how it observe daylight saving before then. Are these important? I do not know.
Can the world simply live with one and only one clock? What happens if everyone observe UTC (Coordinated Universal Time)? Does it really matter that it is 12pm when Sun is at its peak? What’s wrong with mapping “sunrise” and “dinner” to a different clock marking than 6am and 7pm? If millions of people can be taught to change clocks twice a year, they should be able to learn to have lunch when the sun is near the peak, instead of at 12pm.
What’s amusing is the choice between two obvious solutions. The government may order the society to change the clock (what was 11am is now 12pm) or change the schedule (everyone takes lunch break at 11am instead of 12pm). Both are governmental edicts. I like the latter, but the world chose former.