It could be the recipe. The ratio of flour to bananas, eggs, etc. is key. Too much flour and the bread will be dry. Make sure to measure your flour properly. Scoop your measuring cup into the flour, then take a knife or another flat implement to cleanly swipe the excess from the top of the cup.
If you overmix the batter, it will have tunnels and the texture will be negatively affected. Just stir in the flour until incorporated, no longer than that. Overbaking will also create a drier loaf.
Look at the ingredient list. This recipe has sour cream which adds fat, and thus moisture, and contains lactic acid. Acid loosens some of the gluten bonds making a more tender bread.