George V helped with toppling other European monarchies. WW1 was unnecessary and resulted in the abdication of Wilhelm and the end of the Habsburg monarchy as well as the massacre of his cousin Nicholas by communist scum.

Reading more on it, WW1 led to numerous abdications and the end of many German monarchies.

https://en.wikipedia.org/wiki/List_of_monarchs_who_abdicated#:~:text=Ernest%20Augustus%20%C2%A0Duchy%20of%20Brunswick%20Duke%20of,of%20W%C3%BCrttemberg%2030%20November%201918%20Monarchy%20abolished

20 in Germany alone.