The thing is: everyone has an opinion, but the scientific evidence that one system is better than another is weak.

And it is weak because people are different. Some people tolerate clock change better than others, some people function better in summer time, others function better in winter time. Any decision you make (keep clock change, summer time only, winter time only) will benefit some people and will hurt others. And there is not even strong evidence that one solution is better on average.

For the disruption caused by clock change itself, it is indeed noticeable, like an increase in traffic accidents, but it is just one day, but the effect of being in summer time vs winter time lasts 6 months. So if the clock change makes even a small improvement for 6 months, it may be worth the disruption for 2 days a year. I am not saying there is, it is just that there is no real consensus.

So, by default, when a change may have negative consequence for some people and may not lead to an overall improvement, you don't change.