Not exactly: DST solves for not having to have seasonal/variable schedules.
Without DST, we lose that, and we do actually get to decide, once, how we want to arrange our lives in this new, linear time – implicitly or explicitly.
As students often use public transport to go to school, schedules often have reduced service during school holidays.
It will all become more ridiculous 20 years from now when popular demand has lead to offices and schools opening at 9am in the winter and people start calling for a new daylight savings time to get more hours of light in the evening.
The first issue is that DST causes general havoc with all kinds of activities that happen at night, by altering the length of the day and creating missing or repeated hours. This is an unintended negative consequence of how DST works.
The second issue is that DST gives day workers jet lag twice a year by altering sleep/work schedules. Here we have a legitimate choice whether we want to change the schedules in the winter or prioritize consistent sleep schedules instead. This negative consequence arises as a result of changing the schedules relative to absolute time, not as a result of DST per se. DST is merely the vehicle for enacting that change.
To be fair, isn’t that essentially what DST systems are? Literally the way that a society arranges to have everything start an hour earlier or later at different times of year is to designate dates where everyone sets their clocks back or forward an hour.
Granted, it doesn’t fulfill your “all without literally touching a single clock” requirement, because a few types of common clocks still require manual adjustment, but the complaints about DST aren’t about the hassle of literally adjusting the clock on your microwave, right? The complaints are about the sudden disruptions to one’s schedule, especially the amount of sleep one gets on two specific nights every year—and your proposal doesn’t solve that problem. And if we instead agreed to change, for instance, the operating hours of every business twice a year, surely the physical changing of signage would be similarly costly.