Afghanistan, Palestine, US bases in Arab lands and cruel and crippling sanctions against Iraq:

https://www.newsweek.com/osama-bin-laden-911-letter-transcript-12427271

"The American people are the ones who pay the taxes which fund the planes that bomb us in Afghanistan, the tanks that strike and destroy our homes in Palestine, the armies which occupy our lands in the Arabian Gulf, and the fleets which ensure the blockade of Iraq," bin Laden wrote. "This is why the American people cannot be innocent of all the crimes committed by the Americans and Jews against us."

If you strip out the religious speech from the declaration their reasons for doing this are pretty "rational". The religion is mostly the ideological bond between different peoples. Besides some very problematic religious repression.

If the Americans refuse to listen to our advice ... then their fate will be that of the Soviets who fled from Afghanistan to deal with their military defeat, political breakup, ideological downfall, and economic bankruptcy.

The larger strategy was pretty clear, draw the US into unsustainable wars that shorten their "unipolar moment" of being the only global superpower.