Divine Beasts and other key Zelda BOTW elements didn’t return in TOTK for one reason
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.