To add to what @cupe said, identifying country with language is by itself problematic, because that mapping is not one to one.
E.g. I am a speaker of a minoritised language (Catalan) spoken in two different internationally recognised countries (Spain and France). My browser search preferences are set to catalan, with English as a second option and Italian as a third. I don't habitually speak Castilian (the language typically known internationally as "spanish"), so I prefer not to get results in that language if alternatives are available in my languages of choice.
My search options in Kagi are set to international because I have no option to select "Catalan". However, when I perform a local style search like "Caixaforum Barcelona" the results come out it Spanish (for no identifiable reason, given my preferences). The same search performed in Google (that lets me select my preferred language) produces results in Catalan. This alone is a reason for me to not use Kagi for searches where I want to prioritise results in my language (in my case, anything local really).