Take what I said in my BotW review and paste it here. That's what the did for the overworld after all :).

In all seriousness, TotK really doesn't solve much of Botw's problems, and even adds a few of its own, such as Zonai devices not being worth the effort and the depths and sky being vacant of meaningful content.
I give them the same score because it really just comes down to the fact that any problem that Totk fixes from Botw, it replaces with an entirely new problem.