I often speculate that the agglutinative languages like Basque and Kartvelian languages are somehow related
Language Isolates
Interestingly, there are select languages in the world that do not belong to any single language family. With this happens, it is called a language isolate. Examples of languages that are language isolates include Korean, Sumerian, and Elamite. Many of the world’s language isolates are found in Papua New Guinea, which is the most linguistically diverse country in the world. The language isolate phenomenon is also often seen in sign languages, as many sign languages evolve naturally on their own within smaller communities.
https://www.worldatlas.com/articles/language-families-with-the-highest-number-of-speakers.html
https://www.omniglot.com/writing/basque.htm
https://www.omniglot.com/writing/georgian.htm
https://www.omniglot.com/writing/languages.htm