One of the biggest mysteries in Tears of the Kingdom is what happened to all the Divine Beasts, Guardians, and Towers—ancient machines created by the Sheikah to help against Calamity Ganon that eventually fell under his control and attacked everyone.
They originally played an important role in Breath of the Wild but then were nowhere to be seen in Tears of the Kingdom other than in a few subtle nods, like the Guardian built into the roof of the Hateno Ancient Tech Lab.
It was never clarified throughout the story, so players were forced to come up with their own theories as to what happened. The leading theory is they were all disabled and melted down after Calamity Ganon failed.
Today, Nintendo finally shed light on the strange Zelda mystery, revealing that the leading fan theory was actually pretty close to the truth.
The Divine Beasts, Guardians, and Towers did disappear after Calamity Ganon was defeated. The people of Hyrule are aware of this, but they don’t know how or why it happened. Most assume it was because their role was fulfilled, but it’s considered a mystery and no one has tried to uncover the mystery. Not yet, anyway.
What this means is their absence isn’t a gigantic plot hole as some Zelda players have assumed. Instead, it’s supposedly an intended mystery that has been accounted for. Nintendo explained it’s common for mysterious events and strange things to happen in Hyrule, and their disappearance is one of them.
Unless Tears of the Kingdom gets a sequel, which isn’t likely since it finalized the story started in Breath of the Wild, players might never know the full answer.
The next iteration will likely take place at a different point in the Zelda timeline too, similar to other titles in the series, though nothing is confirmed yet.