> their web searches need to be done in French to return reasonable results.

I wonder how much of this is also just the search engine's region setting.

It's a big problem I regularly have with Google. I almost always want English language, US-centric results, so I have my region set to the US. But occasionally I want results relevant to my actual country, and even searching in my native language usually yields much worse results than just opening an incognito tab and letting it default to my real location.