I’ve seen the sentiment expressed before. The logical conclusions of the former, seems, plainly put, terrible.
It would mean one global time, let’s say UTC. Everyone who travels anywhere need to adjust their entire relation to hours of the day.
We’ve very likely always had “time zones”, even before we had clocks and hours of the day. We said “at noon”, “at dawn”, etc.
Where we really fucked up was daylight savings time. But time zones? What’s the alternative?
I think your example is pretty good. The important detail is that the timetable for Bulgaria, would be fairly similar to your own, except it has some kind of offset, which would be more or less exactly what the time zones express. So, instead of everyone that want to relate to some other places’ relative time schedule, having to do it themselves, we just use… Time zones. that’s what time zones are.
Without it, you’d have the same complexities inherent with time zones, but with none of the benefits.
A case of a problem being solved, and mistaking inherent challenges, i.e. the sun moving with a different offset around the world, as a fault of the existing approach. The suggested alternatives would improve nothing, and instead make the problem worse.