It used to be that income was much lower, re-fueling/re-arming/repairing was much more expensive, and 'just playing the game' was the 'credit sink'. Then people whined and moaned. "Its a grind! Respect my time!". So FD gradually increased income to absurd levels, and reduced all expenses into irrelevance. "Where are the credit sinks!", complained the community.
Here, let me grab my crystal ball:
"Carriers are too expensive! Reduce the grind! Respect my time!"
Followed by:
"Where are the credit sinks?! We've been asking for years!!!"
And the saga will continue.
As for the OP: if you play a computer game for thousands of hours across half a decade, eventually you'll kinda have seen it all.
Here, let me grab my crystal ball:
"Carriers are too expensive! Reduce the grind! Respect my time!"
Followed by:
"Where are the credit sinks?! We've been asking for years!!!"
And the saga will continue.