Hussar
Legend
There's plenty of room between "infinite" and just 3 or 4!
Of course, it's plenty easy to chop down possibilities and lay rails. All it takes is lack of imagination.
Only four possible reasons to go to Giant Land? Only five possible ways to get there? That would be 20 adventures already, and I could think of more.
The beauty of it is that I don't have to! The players are likely to think of things I never would have thunk.
That's not entirely fair to characterize reduction of possibilities as a lack of imagination though.
If you are travelling from X to Y over an ocean, it's most likely you're going to do it by ship and that ship will most likely take a single path. A bridge over a ravine is not a railroad.
In other words it is not necessarily true that a reduction of options is the result of a lack of skill by the GM. If the campaign is about sea life and everyone has agreed to that, making the players start on a boat isn't railroading, it's part of the game.