Regarding events in the world and their relation to the party, I used a technique referred to as Displacement, which we've all experienced to some degree or another.
While the traditional 'adventuring hook' could be considered displacement, I believe it has become associated with a more literal style of motivation - active/direct, if you will. 'Press A to continue with Fun.' Actual displacement is more of a passive/indirect form of motivation, something often quite literally ticking away in the back of the player's mind.
In a nutshell, displacement is any device that provokes action from the player. It can be as simple as movement or as complex as plotting a revolution. The example typically used is the timer in Super Mario. Without it you're free to jump around till your heart's content. Another example would be an criminal who has taking hostages and threatened to kill one every hour, on the hour, until their demands are met.
With this in mind, our campaign world is populated by forces that, left to their own devices, will follow a general course of action. The specifics are not mapped out, simply the intent. Each force is, essentially, an NPC but on a macro scale. An NPF, if you will. For example, Faction A wants to control all lumber production across the sky islands surrounding the native's sacred site. How they do it is not mapped out, but we know what they want to achieve - their intent. Monsterous races also get the same treatment, depending on their character. For example, the cyclops are a peaceful race of hedonists, who wish to simple be left alone. The Sky Whales are curious and look to migrate their herds twice a year.
Likewise, an NPF comprises of NPCs, each with their own intents. For example, Freddy 'Woodking' Englewood wants to ensure he's the Master of Projects and is willing to sabotage his own NPF's efforts, if it will help him realise his intent.
All of this is mapped out before hand in a relationship chart and where applicable, geographically.
So, in a way, the world is full of 'adventuring hooks'. However, and this brings us back to displacement - the 'hooks' of the campaign are not reliant on the adventuring party in order to function. Rather, they continue to develop, achieve and change with or without the adventuring party. Conceivably, a player could have their character sit back and simply observe the events unfold around them. What actually happens is, the players travel around, socialising and exploring until they find something that interests them and then take action. For example, the group recently encountered a source of a certain poison and decided to try and set up a supply line, allowing them to sell the poison through proxies at a settlement. They've also attempted to overthrow a criminal organization, save a town from an NPF attempting to conquer it and explored a fair number of ancient sites in the hope of finding treasure.
To my mind, this setup does not feature railroading in the generally understood sense/use of the word - and to be clear, I have no problems with railroading to an extent and have enjoyed many a campaign that makes good use of it. The DM, in this setup, is still making use of hooks to entice the players - each NPF/NPC/site/local/etc is designed to be as fascinating as possible.
The 'trick' is, to let the events continue without them, otherwise we have found that players become reliant on the DM 'feeding them the fun'. If the players choose to sit on their bums and do nothing, so be it. The world continues around them. Once it becomes clear to the players that the world will continue with or without them then they tend to believe (quite rightly so) that they could be 'missing out' - and that sense is the displacement, driving them to take action.
And then, off they go, to annoy some minor official/start a conflict/get taken to court for the murder of a pixie.