I can't think of a single game that manages to have enemies correspond to your level rather than area or story progression actually contribute to the game. It just makes trying to get better gear ultimately a pointless task because the enemies get strong at the same rate so you might as well stay weak.
There is actually a subtle enemy scaling in BOTW that iirc is based on how many enemies you kill (counted by each first enemy defeat, so farming the same bokoblin camp over and over doesn't increase the number). Beating the bosses in the Divine Beasts gives the progression tracker a huge boost, hence why it's associated with them but engaging with the Divine Beasts isn't necessary to progress the enemy tiers.
Some enemies will always be fixed encounters but others will increment through the enemy color tiers as you progress through the game and defeat more of the area encounters. This is why you can actually miss an entire tier of Lynel weaponry if you progress too fast.