Why Are Bananas Berries?
Because bananas meet the botanical definition of a berry.
Yes. Bananas are berries. Strawberries aren't.
Apparently, fruit names are more of a suggestion than an actual classification.
Related Rabbit Holes
So How Did Bananas Get Into the Berry Club?
To qualify as a botanical berry, a fruit generally needs to develop from a single flower's ovary, have a fleshy fruit wall, and contain its seeds inside.
Bananas tick those boxes.
Now, you might be thinking, Hang on. Where the hell are the seeds in my banana?
Those tiny black specks running through the middle are remnants of undeveloped ovules. Most bananas we eat have been cultivated to produce fruit without mature seeds.
Wild bananas are another story. Some are absolutely packed with large, hard seeds.
Imagine peeling a banana and discovering you've purchased a mouthful of gravel.
So yes, bananas are berries. And the strawberry, which literally has berry in its name, isn't.
Botany has some explaining to do.
Further Reading