letting cats roam outside is objectively harmful.
That's very situational. If you're in a rural or semi-rural area that has small wildcats (or foxes or similar) already, adding a handful of domestic cats isn't going to disrupt anything much. The only reason to keep cats inside in such a place is for their own safety (from larger predators like coyotes, and from highway traffic).
If you're in Australia, Antarctica, or a protected island biome with no native small wildcats or canids, or you have a known endangered species in the area that cats are likely to prey upon, that changes the equation. If you're in a highly urban area, that changes things in a different way, because the danger to outdoor cats from traffic and other human activity rises exponentially.
If we're really lucky, those replacements might even become competition for the original products outside the EU, and drive the data vultures out of business.
(Something has to go right in this timeline eventually, right?)