I recall someone I knew that worked higher up in the US government scoffed at the idea of many of the “Government” conspiracies as not plausible due to the sheer incompetence of most government.
Getting them to tie their shoes in unison was difficult enough versus keeping some big secret from the public over the generations.
With the amount of stupid people in the general public as it is I just view it as incompetence as at fault most of the time versus big cover ups.