Space vs. Time

In Lev Grossman’s The Magicians the protagonists come across a water nymph or naiad or whatever in a river. The naiad says she cannot leave the river. Since she is a supernatural entity, she is presumably immortal or very long-lived. Thus, she is very bounded in space, but not in time. Humans are bounded in time but much less so in space.
Which is better?
And doesn’t thinking about it make you want to travel more!?