That would make the ads understandable, but that doesn't deal with the problem that they are advertising something that's not available in my region. For example, if I go on reddit and see ads in English, then only ads for some digital products and services could be relevant to me, because anything that deals with physical businesses would be inaccessible for me.

The only websites I use that are in my native language are the government websites and banks. This would mean that I would not be the target audience of many (most?) of the ads I see.