Skyrim is definitely a gem of a game. I wouldn't however call it "directed" or "central". I've had several playthroughs of it as just a hunter or a spelunker and totally ignored the main story of dragonborn/background war (which is a strength of the game, not a fault).
I would consider Fallout 4 to be much more directed. You have to be the survivor, you have to save the patriots, you have to ultimately destroy one of the three powers. Sure you can ignore the plot for a bit, but you can't advance any storyline. You can't play PI or explore vaults unless you've advanced the story.
This is a false dichotomy.
Skyrim, for example, is absolutely both of these things, offering a strongly directed central narrative and lots of open world exploration opportunities.