Comment by Terr_

Counterexamples that come to mind are Neuromancer (AI driving the plot) and Blade Runner (AI antagonists.)

A compromise thesis might be that in cyberpunk media, AI is at never powerful or motivated to fundamentally reform the worldwide crapsack economic system. They don't abolish corporations, although they might take them over.

Of course, if there was a story about an AI taking over the world into a post-scarcity society, it probably wouldn't be filed under "cyberpunk" either...