OK, but do you expect Valve to do anything about first two problems you have mentioned? (OK, saying “our next console will be a bunch of refurbished PCs we have sourced from local junkyard” would be a flex)
You can see the alternative with PS5 and Xbox, where AMD designed and produced large bespoke custom chips. Versions of these chips which don't fully pass QA could have a few defective cores or CUs fused off and used elsewhere, but we don't see that outside of some very niche Chinese motherboards.
Valve's approach instead allows them to re-use standard PC components which just didn't quite meet muster.
So in effect, "our next console will be a bunch of refurbished PCs we have sourced from local junkyard" is exactly what Valve did here.
But the OP didn't discuss "Should Valve do something about the sorry state of the world", it discussed whether we individually should buy a Steam Machine.