Rampant capitalism is kinda genre-defining for Cyberpunk so Cyberpunk without corporations wouldn't really be Cyberpunk. _The Matrix_ only qualifies as Cyberpunk because within the matrix the machines effectively control the capitalist power structures to exert their influence.

Abundance/scarcity isn't really about availability, it's more about access. You can have a cyberpunk story in a "post-scarcity" setting in the sense of availability (due to sci-fi tech) but you can't have it without unequal access to those resources.