read the study yourself. The most commonly preyed-upon species by cats is birds. It’s a global problem. I will grant you that perhaps cats fit slightly better into the urban ecosystems of Europe, but this is a minor point. They still have an outsized population due to human influence, so they will always be massively disruptive to local ecology. And none of this is considering the danger posed to the cats themselves, whom we all love.
My partner likes to adorn their backpacks and jackets with them. I haven’t found a good use for them. Finally figured out what to do with all my misc stickers once i got a water bottle. lol