For all its faults, the Mercator projection isn't wrong everywhere. On the equator it adds no size distortion at all, and within roughly 15° of the line the error stays small — under about 14%. The countries here sit in that honest band, drawn very nearly at their true size.
That honesty creates its own surprise: because equatorial countries aren't inflated, people routinely underestimate them. Indonesia is the world's 14th-largest country yet reads as small, and the equator's other giants are shown modestly while the northern lands above them balloon. These are the cases where the map finally tells the truth.