It was a failed act of terrorism that served as a pretext for a successful assault on the rule of law in the US.

There's little evidence that Binladen ever had operational command over AQ. His role was more as a figurehead, money-raiser and recruiter. Zawahiri was the tactician. Binladen's objectives, which he repeatedly stated, and which were supported by internal AQ documents that were later obtained, were to overthrow the Saudi state (which failed), to drive US troops out of Saudi Arabia and the Gulf (which failed) and to strengthen the global jihad (which briefly grew, then largely collapsed). He also made repeated calls for the US to convert to Islam, but that's standard Islamic rhetoric. Give 'em an offer to join you; if they don't, it's OK to go ahead and kill them all.

The US assisted Binladen when Russia was in Afghanistan, because Binladen was a bagman for Saudi money to the jihadis. When the Russians were driven out, that Saudi money largely dried up, except contributions from a small number of fanatical Wahhabi minor royals. Pakistan's role was ambiguous: the Pakistani state is weak relative to the military and the intelligence service. The latter two organizations leaned heavily towards Islamism. But the US needed the Pakistanis to at least pretend to be on-side, and to effectively be more or less neutral, during the US invasion of Afghanistan. That meant a big flow of bribe money to Pakistan, and substantial leakage of some of that money to Al Qaida and to the Taliban (a group which was largely created and nurtured by the Pakistani intelligence service, the ISI). And, of course, the Pakistani military sheltered Binladen once he was on the run.

So Binladen was never a US puppet, and, once the Saudi royals realized what his plans were for their cosy family business, he was their enemy too, though, as I mentioned, there were a small number among the 5000 princes who supported him. AQ did, though, have support among some of the non-royal Saudis, as can be seen by the national origin of many of the jihadis including the 9/11 hijackers.

Bin Laden was not removed from CIA payroll after 9/11, or not announced as removed from payroll. Bin Laden was essential in maintaining/reviving US militarism. Bin Laden was staying in a heart of Pakistani ISI/military buildings, when captured. ISIS/Al Quada are US/Israel allies today. Instrumental in invasion of Syria, and in destabilizing Iraq so that they needed US to stay longer.