I find it hard to believe that this could have any significant effect, given all the other negative influences on sleep we already have that seem to be way more

I find it hard to believe that this could have any significant effect, given all the other negative influences on sleep we already have that seem to be way more drastic. In any case, our whole style of life has shifted from the mornings into the evenings, so summertime makes much more sense than having no daylight savings time at all. Summertime for the whole year is definitely my personal preference. To be fair, I live in Portugal, where wintertime for the whole year would be overall bad for the way we live and for tourism, because it means that it will be dark at 8 PM instead of 9 PM. People here mostly live in the evenings and start work at 9 AM and even later. Or, keep adjusting for one hour twice a year. I've never had any problems or complaint about shifting time either. It is nothing, not even a nuisance. IMHO, there is no need to change something that works fine.