As faithful data stewards, GIS users try to keep their data untouched from the source we got it from. Changing data makes the data inaccurate, which will make the map that uses it inaccurate. This is a noble stance, but it is not necessary for a lot of maps. In fact, making the data spatially inaccurate will sometimes allow viewers to better interpret the data and most of the time faster too. A world-famous example of when legibility is prioritized over accuracy is Harry Beck's London Underground Tube map:
This map, while inaccurate spatially to the real world, clearly and effectively shows the data and allows the viewer to easily determine which trains are needed to get to their destination. Having the linear features of the map make bends at 45° angles makes it easier for...
