Bin Laden had gone rogue. Bin Laden was an idealist who wanted to see the return of the Ottoman Empire. Perhaps he had truly planned 9/11 - but I somewhat doubt it. The CIA used an operating cell out of Florida for it. It seems rather unlikely that was Bin Laden's gig, as he was mostly funneling militants to Kosovo during the time the hijackers were living in Florida. While it's possible - I just find it more likely Bin Laden was more regionally focused.
Not that he wasn't a CIA asset - but he turned and assassinated his own senior commander in order to lead his forces abroad from Afghanistan after Operation Cyclone was concluded - a choice which was no doubt motivated by CIA offers of support to fuel a jihad to destabilize powers.
Bin Laden was no fool - he knew he was dancing with the devil, so to speak. The CIA was looking to destabilize powers to put in place its own puppet regimes, much as had been done with Iran via Operation Ajax followed on by a Muslim-Brotherhood backed revolt in 79 which installed Khomeni and the Shah. Bin Laden knew that there was no shared end goal, but intended to use the hubris of the CIA's plans to remove classic western influence over the middle east and replace it with fundamental Islamic regimes which would, one day, buck the Western powers and return to the glory days of the Ottoman empire.
The CIA deemed him no longer a necessary asset and decided to make him a scapegoat for the 9/11 attacks. Bin Laden's networks have largely been absorbed into newer operating cells termed as the Islamic State - though that particular group has been effectively neutralized by this point.