It's also true that there are second order effects, like for example all the mining hardware dedicated to ETH needs to find a new home, which will depress prices for new mining hardware for "chains that are hardware-compatible with old ETH", and thus probably support their prices a bit.
[1] And do, I think. IIRC there was a stat rolling around a few months back showing electrical grid usage dropping due to the crypto crash, but can't remember where it was or how reliable the source seemed.
[2] Though AFAICT no one is tracking exchange rates for it yet, so your guess is as good as mine as to its value.