Industrial produced bananas are harvested, stored and shipped so they arrive on shelves just becoming ripe; supermarkets don’t want green bananas that people generally won’t buy right away. Banana shipping is actually pretty fascinating logistically, the fruit is climate controlled on it’s journey so at different destinations they arrive at the same ripeness; buying a banana in Miami and Seattle are about the same which is pretty unusual for fruit.
Organic bananas don’t have the same considerations, they will still be harvested with the fruit at the same age but will end up on shelves sooner.
They are nutritionally identical. They are also one of the crops that there really isn’t the same considerations for pesticide usage as the skin is so thick and it’s the plant that is treated not the fruit. The big reason to buy organic is to avoid chiquita who are one of the most evil corporations in the history of the world.
BTW if you live somewhere where you can grow your own it’s a low maintenance plant and well worth it. Plant ripened bananas taste much better and last longer. You can also grow varieties that are not commercally produced due to Panama disease risk, blue java tastes like vanilla ice cream.