On the other side, equatorial countries have about the same sunset and dawn all year long. Again, DST is useless.
Where DST is useful is in a place like the one I'm living at, at 45 degrees North. I'd go with permanent DST plus an extra DST in summer. Basically it's what Spain have been doing for almost a century.
It's cloudy and still reasonably bright outside here. It will be dark past 22:00. I'd take an extra hour of light in the evening and darkness until 6:00 in the morning. It matches the time people goes to sleep and wake up here.
As I said before, changing the clocks is a much more efficient approach than getting every school and workplace (etc) to change their hours.
It’s not true IMO that “plenty” of northern countries do without it. Russia doesn’t (since 2014) but their time zones are a mess anyway. Iceland doesn’t. Otherwise pretty much every European country does.
Not 100% sure on those stats. They come from AI, and I only spot-checked it. But yeah. Most northern climate countries do currently have DST.