Solo/co-op could just simply have a slightly diminished experience accrual rate than conventional modes.
In 2042 I used this mode to practice or grind certain guns or vehicles. I'd argue it is more responsible than throwing away aircraft while practicing in other modes.
the solo/co-op mode in 2042 you earned less xp fairly certain it was half the xp and you got a first match of the day bonus for xp gains.
I just don't understand why ea/dice don't do that again for the portal or just add in the solo/co-op bots modes it would make sense and it would make people happy
