A wide body offers better cargo potential and flexibility in configuring competitive premium cabins.
If that is less important (e.g. leisure market, opening up new routes, thin routes etc.) a narrow body offers superior OEW, drag, single aisle crew efficiency and most of all: fuel efficiency. Wingletted 757s made an impressive revival during the last few years on the Atlantic..
And Tu-204 is collecting new orders, and launched a new improver Perm PS-90 engine model.
Arenīt the Chinese also planning a plane with over 150 seats AND over 100 t MTOW?