Hi, totatodev, thank you for reviewing!
I think that as you progress on the side biomes (desert and cold islands), it gets harder to harvest without being hit here and there, but you are correct, the game is not well-balanced at this point.
Some upgrades are still relevant for harvesting, like damage for destroying ores faster (gold and sapphire, I think, have high health), and speed prevents you from losing falling resources.
But definitely some balance is required to make the game feel more cohesive, and even allow different ways of playing it (e.g. not aggressive to towns).
Thank you again for the detailed review, and the kind words! 😊