If you like the apples made by a particular tree, and you want to make more trees just like it, you have to clone it: Snip off a shoot from the original tree, graft it onto a living rootstock, and let it grow. This is how apple varieties come into existence. Every McIntosh is a graft of the original tree that John McIntosh discovered on his Ontario farm in 1811, or a graft of a graft. Every Granny Smith stems from the chance seedling spotted by Maria Ann Smith in her Australian compost pile in the mid-1800s.“Why Your Supermarket Sells Only 5 Kinds of Apples” by Rowan Jacobsen
A fascinating article on the history, genetics and economics of apples.
With bananas is worse… AFAIK there are currently only 3 kinds of them on the market, while all the other "variants" are almost extinct…
That's what my research indicates as well.