@Kernic
I would be careful in concluding that foreign laws apply to Kagi.
If you think about it, then Kagi would have to adapt to every law in every country in the world they serve. Including blocking search results which disrespect German politicians, since it is illegal to insult the Chancellor in Germany. They would also have to block all results which goes against the ideology of the Chinese Communist Party, since that is law if you want to do business in China. As well as block gambling websites to follow the law in Brazil, results that insult the monarchy in Thailand, and so on.
While I agree that it's a good idea for Kagi to present prices with taxes included, or with a dropdown country selector, threatening a company in the manner which you are doing is never a good way to get your feedback heard.
When a customer starts talking about "illegal" and the law in this way, that is understood as very hostile and most businesses will cut contact with you then and there and refer you to speaking only to the lawyers. Because you're talking like you're going to sue them or like you're about to file a report against them with the Polizei.
In practice, no country tries to go after foreign sellers. The responsibility is put on the purchaser within their jurisdiction. They don't go after sellers of physical goods, much less digital services.