1. That an image is expected to be decompressed as a whole, and
2. That an efficient (de)compression is possible with generic compression algorithms.
Both are false. Even PNG does its own filtering, a pretty rudimentary model but much better than just DEFLATE. QOI is much better in this regard because it has a (fixed and also rudimentary) model; it was a clear demonstration that modeling is much important than entropy coding.
1. That an image is expected to be decompressed as a whole, and
2. That an efficient (de)compression is possible with generic compression algorithms.
Both are false. Even PNG does its own filtering, a pretty rudimentary model but much better than just DEFLATE. QOI is much better in this regard because it has a (fixed and also rudimentary) model; it was a clear demonstration that modeling is much important than entropy coding.