Perhaps it's us who stays the same, and it's our tools that move around and evolve

Actually, the world is divided into 24 main time zones that are each 15 degrees of longitude due to the fact that the earth rotates 15 degrees every hour.

The reason for the discrepancies is due to transportation, travel and communication within a specific area. Changing time would be too cumbersome if people are frequently traversing across the zones, so it's simpler to keep one that is uniform.