From article : "Maybe one cave system has a place where it connects to a dungeon, which connects also to a basement in some guy’s house in the middle of nowhere."
This just sounds better than having the black and white delineations between spaces. Yes!
To an extent, tears of the kingdom really does do this a few places, but not enough. It really is fun finding new holes into the underworld from a cave, and using the caves to get into the shed in that one village or to the tower etc
That said, I was also surprised ToTK had the same plot as BotW. Like, Ganon takes over the castle and then they defeat him and then they go into the basement and he's just there and he takes over the castle again?
[1]: i.e. one with 4-8 dungeons and new navigation/combat tools in each, not a sandbox like BotW