Living in one city could only ever introduce one to the culture of that one city. To understand the world, one had to see the world in some capacity.
For earthlings, this wasn't too hard. The internet made it easy to connect with others and learn of their circumstances regardless of distance. Cultures became prominent, and melded together to form new forms of culture.
It was a truly interconnected world, but surprisingly enough, it was also an outlier.
Perhaps it was because mana was a new thing for Earth.
For most worlds, mana would awaken before life managed to take root. The presence of mana would transform the environment, making it inhabitable for life forms.
This was why certain concepts of physics were ignored as the worlds in the universe drifted down their own paths. Mana had fundamentally altered those laws for its own benefit.