Co-op vs AI Intermediate bots stop buying items

I've been finding this is the standard operating procedure for most of the older champion bots, particularly on maps other than Summoner's Rift.

Relatively newer champion bots, particularly Lucian (always), Darius (the rare ones that remember they have like...abilities...to use) and Renekton (when paired with other smarter bots) seem to be able to surpass this crippling limitation. I've even seen exceptions with among some of the old timers (Ryze, Annie, Ashe) as well, though this tends to be when they've been incessantly fed early game (typically by an even dumber bot pretending to be a player).