[Okay, but if you had a giant Ferret you could ride across the water like some ridiculous living pool noodle, you'd do it even if you didn't have anywhere to be, wouldn't you?]

Weeell...I guess, but if you can use Fly you won't even need to worry about the routes! You could just fly to wherever you wanted to go. Plus, there's a whole lot more to see in places other than Goldenrod. Lots of different Pokemon, too.