If everyone did it, it would work fine.

Business hours : 1 hour after sunrise until 10 hours after sunrise.

Even without that, many of us have flexible hours and can either start work earlier, or just do something before work when we have time. Waking up early in the summer means you can catch a bike ride or take a short run or hike before work. Since it's too hot in the afternoon/ evening this works quite well for much of the country.

It would be massive mess. Unless we tie large regions to some specific point. Entire idea of timezones was to get rid off local times. Bringing them back would just cause more issues specially in current world with all the electronic communications we do.

The time when sunrises changes both when travelling west to east and south to north... Not to even mention being beyond artic circle. Where sun never rises or sets at least on some days...

Yeah, but it's not possible for everyone to do it, because sunrise changes depending on both your latitude and longitude. Some places the sun never sets and rises for months at a time. We interact with businesses that aren't close to us.

For those who are just doing it on their own, I think DST actually helps them. The government creates a very rough movement following sunrise, and you can use personal adjustments to zero in on the exact sunrise time.