I'm sorry to make you feel that way.
That part was intended to be a shocking pitfall that you may fall in after learning to dash, and if you've tried to reach the top platform before entering the cave you could apply everything to find a shortcut by jumping from the tree.
But since the game world is quite small, I just placed these two segments too close to each other, not allowing you to get used to the dash, and not giving enough hints that you can skip the cave entirely if you already know how to move.
This is an important lesson for me to learn, thank you for sharing your feedback, and, again, sorry for that!