FilterQuality.low corresponds to linear sampling with the base mip level only (with Skia). Flutter's image widget uses this as the default filter quality for rendering. Unfortunately this has major fidelity/performance problems if the image is substantially larger than the destination rectangle (a common issue).

Avoiding mipmaps will impact image quality, as entire rows/columns of pixels will be entirely dropped.
Avoiding mipmaps will slow down rendering. While a small image will sample fewer pixels from the larger image, these pixels will necessarily be more spread out causing increased L1/L2 cache misses.

Mips solve both of these problems.

Impeller initially implemented FilterQuality.low incorrectly and gave it mip levels. We do not plan to fix this until the framework is fixed, as it will have a negative impact on all Flutter applications.