Commonwealth- What's so common?

There is a lot of buzz around the Commonwealth Games and whether they should be held in Delhi given the current environment and so on. This triggered a thought in me.

The term Commonwealth has always intrigued me. What is so common about the Commonwealth? Did Britain not suck the lifeblood out of its dominions and in fact, misappropriate their wealth for their misuse? What locus standi do the British have to create a common body of their former victims, put themselves at the drivers seat, call it the Commonwealth, as if the combined wealth of this body of victims is still “common” and therefore, accessible to the empire? Is this not Imperialism 2.0?

Why, on Earth, are the victims of British imperialist fascism still hanging on to the notion of Commonwealth? It is their wealth, dammit, that Britain is wrongly parading as its own, by creating a facade of commonality. If these victims had any sense, they’d
a) Ask Britain and the United Kingdom to leave the Commonwealth
b) Rename what remains as , I don’t know, the “Organization of Nation States Oppressed and Victimised by British Imperialism”
c) Demand return of misappropriated wealth from Britain with interest, and due compensation for all lives lost in the quest for independence of these nations.

But no, these nations choose to play it along, and the rump Imperialist power continues to play pied piper, sponging off its ill-gotten gains. Strange are the ways of the world.