We've gone over this ground pretty thoroughly here on the Zone.
I suggest you review previous entries in the Space/Science pages here on the Zone.
I also suggest you review the essay in centauri-dreams,org, A Seti Reality Check:
https://www.centauri-dreams.org/2020/07/03/a-seti-reality-check/
Both the essay and the critical reader comments are a good intro to the subject--for both sides of the question.