It is not a binary. But published adventures tend to be rather scripted which easily leads to railroadyness, especially in hands of an inexperienced GM. I said this as this thread was started by a publisher using their three-path adventure as an example. A published adventure cannot contain information about infinite number of paths that the characters could theoretically take, three is already plenty.
I have seen a few "sandbox" adventures, which are locations populated by critters.
I don't think I've seen an adventure that does what I want; a location adventure where
(a) The multiple different critters/factions have plans, and triggers, and time tables.
(b) There are adventure hooks spread through time and space in the setting.
Imagine a micro-west-marches, but with an adventure set in.
(a) There is a Kobold tribe, new to the area, attacking an overland trade route (for supplies). They are doing a ritual in a ruined temple.
(b) There are highlanders which the village thinks are the ones attacking the trade route (the village pays tribute; they think the highlanders are breaking their deal).
(c) There are pirates planning an attack on the some shipping. Their spies are in town.
(d) The local priest is involved in a conspiracy to replace the baron with someone more suiting.
(e) Members of a cult of a snake god has followed the Kobolds to the area. They want to interfere in the ritual (well, steal the product of it).
then some other relatively unrelated stuff you might run into:
(f) A Dire Wolf has taken over a local wolf pack.
(g) The Emperor, a Griffon, has a mate that is sick, and a fresh clutch of eggs. It is upset, but could be bargained with using magic.
(h) Fizzbottom is working on a gnomish positioning system, and needs adventurers to calibrate it
Then tracks for "what happens if the players don't interfere", hints that they are around (random tables in and around the town, insight check DCs, perception DCs). NPCs that are looking for help, and how they are looking for help, what kind of PC they might accept as a suitable helper, and what they'll offer, and their motivations.
Then some possible external hooks; what kinds of organizations might send PCs as agents to this town with a mission connected to the above (for easy initial startup): Merchants Guide, Researcher looking into a prophesy about the area, Disgruntled pirate, Agent of King over the mountain, Serpent cult hunter, Serpent cultist, Highlander sent down trying to find out where the tribute and traders are, etc. None of these are required, just possible additional hooks.
Meh. Maybe I should just write it.
But are you aware of any adventures like this?