Aside from the awful level design, nothing really.
I never really understood your aversion to OoE's level design. As far as I'm concerned, it inherited the solid level layouts of every Metroidvania game before it. The game's first half took more of a linear, "travel"-like approach, but nothing otherwise struck me as particularly jarring or different.
It tried to be a modern day Simon's Quest but suffered from the same design problem, in that every encounter needed to be easily accessible from both sides due to the need for backtracking. This led to a lot of "floaty" enemies and "wall" enemies, and not a lot of laid out encounters like something you'd see in any of the Classicvanias or memorable rooms like Symphony of the Night.
That comes with Metroidvania territory. The entire genre insists heavily on backtracking, so it definitely isn't OoE-specific.
It also had its fair share of reused rooms as well. I particularly remembering one mountain level using the same bridge room at least three times.
That's actually true. Entire areas, let alone rooms, were reused, but I assumed it was intentional. Every outdoor area in the game has its duplicate, only with different color schemes and mild design differences.