What 1600×1200 is for
1600 × 1200 is a resolution with real history. It is UXGA, the top end of pre-widescreen monitors, and it is what a 2-megapixel camera produced — the standard consumer resolution for years.
It remains genuinely useful because 4:3 is still the native aspect ratio of many projectors and of most phone cameras, so images at this size display without letterboxing.