While I like the game, it's reuse of the world of Breath of the Wild makes it much worse and the additions don't change or introduce enough to make it feel like a new game.

The underground and sky sections are pretty disappointing. The first time you descend through a chasm it really feels like a whole new world with so much mystery. But there is actually nothing much to the underground. It lacks people, quests, enemy variety, rewards and overall distinctiveness which lead to it becoming very uninteresting. There is just a single main-quest that encourages open exploration in the underground, and it is pretty unnecessary to the story. Treasure maps lead you to find supposedly exciting equipment, but almost all of it is just mediocre fan-service armor that is not grounded in the game world.

While the sky is better it still has its flaws. Exploring is again not very fulfilling. Island archipelagos are often very linear in their design and the navigational challenge present in the initial tutorial area is almost completely missing.

The whole world lacks new landmarks. The two new biggest are introduced right in the beginning.

There are many systems that needed more done to them. The armor system with still is the same and remains not very interesting, exacerbated by the fact that most armor sets are rehashed from the first game, which are also the best and most easily upgrade-able sets. They could have done so much here and the fact that it is unchanged sticks out like a sore thumb. A pet peeve of mine is that Links new hair style gets overridden with the old hairstyle on any head accessory, what a waste.
The combat remains unchanged as well, there a no new moves or weapon categories available to the player.

But in the end, it is still BotW with extra stuff and it retains most of its good points, even if they are weakened due to the reusing of many game elements like the world and armor system.