Linux

That's fair, but come to think of it, the architecture of the CPU doesn't really say anything about privacy. Someone can build an RISC-V chip but sneak in telemetry, or you can build yourself a x86_64 CPU and be 100% no telemetry. It's about the manufacturer, not the architecture.

I don't think you can ever be 100% sure that the CPU you're running on is telemetry-free unless you have those kick-ass X-ray machines and examine it yourself. Building your trust on top of something else you deem trustworthy though, is practical. Billions of people are running Intel/AMD off-the-shelf CPUs, and there are perhaps millions specialists in them, what is the chance that a backdoor remains hidden?

The same goes for software. How do you know Linux kernel, OpenSSL, Wayland is trustworthy? Because many people use them, and it's unlikely a backdoor is there. Think about the sheer amount of software the CPU runs. Don't you think we shall have a greater concern there?

Hopefully this calms your paranoia about hardware a bit.

That is fair enough. Have there been any findings that CPUs are sending telemetry of some kind, or is it more the idea of there possibly being some back door for governments to use?

I guess for me personally, my threat model for privacy is more towards foiling corporate data harvesting wherever possible, but I have resigned myself to the realization that making a computer nation-state-proof is borderline impossible without unreasonable levels of effort, especially for a normal computer user like myself.