timezones are absolutely helpful from a logistics and coordination standpoint
They’re a downside from a coordination standpoint. If everyone was on UTC, you could say “the meeting is at 04:00” and everyone, anywhere in the world, will know when the meeting is. In the real world, you have to say “the meeting is at 2pm AEST” and then someone in AEDT will have to think “oh, that’s 3pm for me”, and someone in American EST will have to convert to UTC and then convert to their time. It’s a huge pain.
So what if it will be dark well into morning wake hours in the winter
That’s not something that DST does. It would be something that switching to year-round DST would do, but permanent standard time doesn’t change winter hours at all. It can mean you might have dark mornings (especially early and late summer—after the switch to DST and before the switch back to standard time), depending on how far west you are in your time zone and how far away from the equator you are. That’s the main thing DST does: swap bright mornings for bright afternoons in summer. Which is kinda silly considering it’s done at the time of year when afternoons are already bright for the longest. It’s also very harmful to public health.