You seem to be viewing the government as just one big entity and ignoring the many tentacles that are attached to it and the compartmentalization of the departments, and even within the agencies/departments themselves.
Not to mention the backgrounds and loyalties of some of those within the government branches that most certainly could facilitate any number of things and outcomes.
You also rather naively dismiss the real threat of bribery, and political and physical death and financial ruin after years of "hard work" that are at stake.
Perhaps you might do well to brush up on the machinations of government and history before you involve yourself in a 9-11 conspiracy discussion.
A good place to start would be what some of the whistle blowers and those in the fields pertinent to government and the 9-11 attacks have said regarding their objections to the the official version of events, followed by the objections of credible people in science and physics pertaining to the destruction of the WTC buildings.
There are many who do not have some sort of dependence on government, financially or otherwise.
Skipping all the way to the who, why, and how is going to make you ignore the very first and important reason there was almost immediate doubt the truth was being told in the first place.
Not knowing those 3 parts does not in anyway dismiss the physics and science behind the 9-11 events, or the improbability of the NIST report being accurate, or scientifically sound..
The reason there was "immediate doubt" about the truth of the official 9/11 story is the same reason there was "immediate doubt" about Sandy Hook ... slimy CTs who know they can get silly CTs like you to bite on any story they author no matter how silly. For them there is fame and some coin and for you there's the mess you make in your pants every time you read one of their fictions. You are forced to reject things like the NIST findings because they interfere with your CT religious beliefs.
No the immediate doubt started when massive structures were exploded (not collapsed) and their rapid rate of decent through the path of most resistance did not coincide with them being made of steel, and this unprecedented event (their actual destruction) not only occurring once, but twice, and then a 3rd massive building "collapsing" without being the target of one of the coke sniffing, freedumbs hating, devout Muslim jihadists plane.
Official state conspiracy theorists like yourself seemingly have no ability or desire to look at this subject with any objectivity, and dismiss the states conspiracy theory's lack of credible proof and evidence, depending instead on an adherence of strict loyalty to their authoritative figures and agencies, despite historical precedence of numerous lies.
You depend on reports that rely on unsound data and calculations, and just plain ole bullshit.
Hell it took a regular citizen to point the fact that WTC 7 experienced a period of freefall for the first 8 stories.
The dogmatic fanatical beliefs that official conspiracy theorists like you have is most likely based on fear and cowardice, that the realization of what is happened and continues in the nation, is too overwhelming and too much to accept and comprehend.
It is you that is afraid of shitting yourself, so you deny even the mere existence of a possibility of the CT's that you fear so much.
BTW, the NIST report has been taken into account, and it actually is at the center of many points of the objections, since you bring it up care to explain why they refuse to release their computer simulation data so that others in the scientific community can replicate the outcomes? I doubt you will, so run along now, unless you wish to debate that which might cause you to soil yourself.