I once had a job making ice cream and it bothered me that I had to add yellow food coloring to the banana ice cream. We used real bananas and didn't add banana flavor. But I was told to add yellow color anyway.
Banana flavoring is also based on the flavor of Gros Michel bananas, which is why it doesn’t taste like the Cavendish bananas commonly available today.
If you want to see a very yellow inside of a banana, get a very ripe plantain (completely black peel) and fry slices.
Making food aesthetically pleasing does add flavor to that first sample.