Would be best where they don't have cats, like the Americas (since local felids seem to be too big and/or too shy of humans to bother with hanging out around their settlements compared to Old World wildcats). It seems like that in the Old World, the benefits of wildcat domestication was great enough to ignore competing animals. It certainly isn't hard to attract feral cats even today. Some theories suggest the word "cat" is from an Afroasiatic language, like those languages perhaps spoken by people where cats were domesticated (but this is controversial, since the Egyptian word for cat is derived from the sound cats make i.e. "meow"). And the Chinese had the leopard cat domesticated at one point, but they abandoned it in favour of the African wildcat and nowadays the leopard cat's only importance is as part of the stock used to create hybrid cats.
As a fellow cat lover, I'd love if the East Asians kept the leopard cat domesticated. Maybe find a way to get the fishing cat domesticated too (housecats seem to like to drop their toys in places like your doorstep, their food/water bowls, etc, so fishing cats can grab fish for people?), and the Mississippians domesticate the bobcat (could be good as a fur animal in addition to removing agricultural pests) while in Mesoamerica, the ocelot is domesticated and in South America, the margay is domesticated. Perhaps the Russian fox experiment might be directed toward lynx TTL, and you'd no doubt end up with lynx which resemble domestic cats in coat and temperment.
Overall, a "peak felid" TL would be pretty great, since in addition to all sorts of felids which would be easy to adopt (and all the weird cat hybrids which would exist), conservation of felids might be further than OTL.