Collecathon 
Maybe Mario 64, but Sunshine and Galaxy go out of their way to mix things up. In Galaxy you never visit the same area or go the same route in a level once on later "missions".
But you do revisit the same level over and over again right?
This is a weird thing to complain about given that Mario 1 has repeat levels.
And in past Mario's, you have worlds which have the same basic art design, but different levels. The same is true here. It's the same world, but different levels and sections open up on different levels. So while it's the same stage, you're completely different places with completely different goals, so the outcome is something that plays out like it's a completely different level anyways.
Your point is redundant, especially given 2d Mario's history.
Watch these videos. They're the same world but different levels.
