They can make money on trunk services, as it allows people to
travel longer distance.
I think that is why feeders 220, 226, 290, 294, 321, 322, 326, 327,
328, 382 & 385 as well as TownLink 357 were replaced with trunk
routes.
Not to mention the demise of 227, 274, 331 and 371 due to
duplication by other trunk routes.