Whilst PoC seems to nicely complement PoW, proving capacity usually creates insane wear on the HDDs and SSDs used. Thus, a lot of waste is generated, and there is no real advantage over PoW.

Maybe this could change when using workloads that are actually useful as a side effect, e.g. for archiving, in order to prove capacity. Until then, I don't see enough advantage in putting resources into PoC schemes.