My brother has shown me some information from WWF about letting domestic cats roam outside freely. Apparently we should not let them do that cause they are beco

My brother has shown me some information from WWF about letting domestic cats roam outside freely. Apparently we should not let them do that cause they are becoming a threat to the bird populations (we have a cat and we let him go out whenever he wants). I though what a crazy joke and we laughed it off cause cats are, after all, animals and they act accordingly, sometimes killing birds. Then I thought - what if the population of cats became so large that it indeed became a big problem? What if it causes ripples in the ecosystem that affect other species? And finally: how can I know anything about it to discard it on the spot? Similar to how some people are against vaccines or even masks because "they don't work and can only cause harm" ("I'm no doctor, but I ain't stupid!" (tm)). It was a small but humbling thought when I realized I fell for the same thinking trap that I accuse others for. Even if this particular information on cats were to turn out totally false and a part of evil leftist agenda I should really keep an open mind and dig deeper, especially when the news sound insane (to my worldview) but come from a large institution or a well established source.