For large freighters, cargo jobs actually don't pay much more than charters. Urgent cargo jobs however pay substantially more; the only downside is they're difficult to find. I think urgent cargo jobs should be made more common, making them more competitive against corporates especially for mid/later-game grinding.
Pros: Would make freighters, transport planes, and any other vehicle capable of doing cargo jobs more economically viable. Especially with extremely large transports like the An-225, C-5, etc. which already have very poor profits given their price.
Cons: 

but this also affects other planes too!!!
except maybe the C990