> Every flat map projection distorts something, so every projection has to optimize some parameter and trade off other utility. I'm constantly amazed at how hung up people are on apparent size of countries. If size is your thing, use some other projection!

That's the point of the post. The trade-offs between different projections are rarely discussed, considered or even mentioned outside very small cohorts because there is a specific shape of the world map that most people who are not map-heads or spherical projection experts take for guaranteed. Get a non-Mercator projection map and put it in your dinner room, and then see how many of your guests will comment about "so.. why is this map weird? It doesn't look right?" then tell them "every flat map projection distorts [...]"

> Mercator is and remains popular because it preserves local angles and shapes, which makes it simple use this projection to navigate by rhumb lines (compass headings). Because most maps people are exposed to are designed for navigation, it is the most commonly seen projection. And yes, it distorts size and is largely unusable past about ± 70º latitude. Every map is a compromise.

Out of the millions of decorative world maps on walls, kids with maps to learn the world, world maps on the news, maps used in data visualization charts etc., non of those are using the map for "navigation" yet they still use Mercator projection simply because "that's the right shape of the world" regardless of what "right" means. Not because they evaluated the compromises of the different projections and figures "oh maybe someone will be lost at sea and only have access to our GDP per capita world map visualization, better use Mercator projection to preserve local angles and line up with compass headings"