Do most Intel (and by extension, Linux) machines have SHA2, though? I think it’s a pretty recent extension and at least initially, they were only shipping it in their low-end embedded models.
All AMD Zen processors have the extension.
This is incorrect. Intel only launched their 11th gen desktop processors March 30, 2021. The 10th gen and earlier desktop processors do not have the SHA instructions. You can still buy a new i9-10900k from Newegg today.
(Note that 10th gen Intel mobile/laptop processors are a different micro-architecture, and do support SHA.)
Edit: Perhaps you're thinking of the AES instructions? They've been around a lot longer.
> The argument here is that many (most?) Linux systems have access to a hardware SHA2