The 'grabby aliens hypothesis' is quite compelling and many astro physicists and biologists seem to consider it even more plausible.

Basically, a series of hard steps need to be accomplished, and the galaxy, at least, is too young and too hostile for it to be swarming with intelligent advanced civilisations.

Fermi paradox has been around a while and there are few other theories, 'dark forst' as an example too. So I wouldn't succumb simply to such a basic and old concept when so many great minds have come up with plausible reasons to counter the great filter.

E: I guess this isn't a thread for discussion then...

E2: I just realised I'm in r/furturogy, makes sense now...