Does it seem odd that Charlie was knighted. Apparently he was shunned by Englander's for skipping out during WWI. Then he had little interest in going back. Other than being born and spending his early years there, did he ever actually do anything to honor England?
Note that Chaplin was knighted as late as 1975, approaching 86, two years before his passing; a knighthood had been suggested as early as in the 1930s, but was then turned down, reportedly due to Chaplin's not fighting at the battle-fields during WWI (his Liberty Bounds tour apparently didn't count). In the 1950's, a knighthood was suggested again, but turned down due to Chaplin's recent troubles in the U.S. (Source: "Chaplin and American Culture, Charles J. Maland, among other books)
As to whether Chaplin did something to honor England; that depends on what one considers "honorable service" to a country. The understanding of such terms has been much broadened in later decades, also in royal circles. In this case, it was Chaplin's immeasurable contributions to the film medium as well as all the laughter he'd given a whole world, including England, for generations that was being acknowledged.
War bonds tour vs serving in the military? Anyone who questions the lack of a knighthood simply does not understand the impact of ww1 on the British people.
WW1 service is a HUGE deal in the UK. So many of the aristocracy lost their “heir” in what the Brits still refer to as “The Great War.” In Testament of Youth, Vera Britten describes the enormous loss of her brother, fiancé, their Oxford friends, and literally every single boy she had ever danced with, in that war. Rudyard Kipling went to great lengths to help his son get into the army (today, we would describe him as “legally blind”) because fighting in that war was the DUTY of every Briton. An entire generation of young British men died on French battlefields.