[promiseofbeans]

Every 2D projection of a 3D surface will be wrong in some way. It's just a matter of which attributes you want yo compromise on and which you want to be accurate.

As I understand it, Mercator mostly preserves relative distances between continents, at the expense of distorting continent shape & size. This is useful for ocean-based trade route calculation, which was a major concern when Mercator was introduced.

Most regions these days have a standard projection they use that best represents their country and modern GIS software can trivially reproject data in whatever format your project is using.

For example, in NZ, New Zealand Transverse Mercator is normally used. We used to use New Zealand Map Grid, which better represents our country, but the govt decided to switch the official one to better integrate with overseas data & software. Modern software allows you to trivially use either though.

Tl;Dr: map projections matter, but different ones are better for different purposes in different places. The African Union can use whatever they want, and everyone else can use what is most useful for their maps. No need for everyone to use the same system when we can use both.

[alanbernstein]

This site's claim is that it is important to Africa for other regions to normalize using projections other than Mercator.