For the FOURTH time I ask you- Do you think we know all there is to know about interstellar travel?
The fermi ‘paradox’ is an intellectual exercize- nothing more. For thousands of years we had no ovidence of ‘electrons’ but that did not mean they didnt exist. the same argument applies- there are probably many things we have not yet seen evidence of- but they do exist.
You sound like you read a thing or two and formuilated a rock-solid belief. This is all theory.
What I am saying is that there is nothing in physics that would lead me to believe that the question you proposed is even relevant.