Another positive aspect to AI is it could equalize some of the gameness.
"Huh, equalize gaminess with gamey AI players!" Yep.
In addition to countering unchallanged milk-runners...
I observed one player that is VERY focused on score during a low player numbers time. First he de-ACKed the town in his LA7. Then using an M4 with rockets drove into town. First he used the rockets at point blank range then gun (unchallenged in any way) to down the town to white flag. He then brought a goon. When I could participate (was on a call) I upped a plane and shot that goon down and kept CAP until he gave up on that base.
Made me wonder how many times he and others do this. Seems like just a few AI opponents here could go a long way.

EDIT: My statement that this player is very focused on
score is fact. Over seeing him do this and other similar tactics for
years. He tends to finish in the top 10 if not 1st some times. Not gonna name names. Just mentioning this as an abuse that is SCORE driven.