Politically, Cross Country has the massive benefit when you the consider the "levelling up" mantra of
a) not serving London, and indeed barely touching the southeast
b) connecting up the regions of Britain, including "red wall areas" of Northern England, the Southwest, the Midlands, Wales and Scotland
Thus I can see real political capital for Boris or a future PM to announce a big increase in the number of carriages on these services, bringing the 3 nations together, improving connectivity in all those marginal seats in the North and Southwest etc by moving the 222s over.