It was not born out of necessity. It was born because of the way your brain percieves the images. There is no need in adding detail if your brain can live happily without it.
And if FLIF achieves such great lossless compression, imagine what amazing compression you can achieve with lossy compression.
Let's take a step back. Why did developers start to think about how the brain perceives details and how to trick it in the first place? Out of a necessity to save bandwidth and/or storage space.
And if FLIF achieves such great lossless compression, imagine what amazing compression you can achieve with lossy compression.