In countries where cats are native, they have significantly less impact on wildlife, or at the very least form a part of an ecosystem rather than being a manual introduction (admittedly one complication here is cat populations grouping up in suburban areas). As for safety for the cats, in their native countries they don’t have any serious predators to harm them.
I don’t know if Finland is considered native for cats but it’s against the law to let cats roam freely because there’s a very real risk of them getting injured, disease or dying. Not just from predators but from humans and cars and so on. A dead cat on the side of the road is a too common of a sight. I think the effect on wildlife is seen as secondary and the welfare of the cat is the foremost reason for it.
British cats go to cat school as soon as their eyes open so we have very smart cats that can navigate roads.
I live in the UK where there are an estimated 10.8 million cats and have literally never seen “a dead cat on the side of the road”. I appreciate that it is a real risk and that it does happen, but you’re either blowing things out of proportion or there is something weird going on with Finnish cats and or Finnish drivers.
Found this
230,000 CATS IN THE UK ARE RUN OVER EVERY YEAR!
Statistically only 25% of road traffic accidents involving cats are fatal, so the chances are good the cat can survive with urgent care - instead of being left to suffer a painful death.
https://www.cats.org.uk/teignbridge/news/animal-road-accident-awareness-day