After decades of problems with seeding RNGs, why isn't there a electronic circuit that gets a seed from quantum noise or something like that? The circuit could be part of the CPU or support chips.
After all, amplifiers are always trying to increase the signal/noise, and the basis of the reliability of digital circuits is avoiding the noise. Instead, a circuit can amplify the noise and sample it.
There is. RDRAND for x86/x64 has been in all Intel/AMD for several years.
Most ARM SoC have some equivalent device, but they are nonstandard and require driver support.
Even the TPM chips in basically every desktop, laptop, and server for over a decade have hardware RNG. Again driver support is needed.
The problem is cheap “blue plastic boxes” may not have a hardware RNG, nor will Virtual machines or containers. Writing code to figure out what RNG is available and how to use it is a nightmare so few people do it.
This is why most security people say “use the OS CSPRNG always”. That way user-space code doesn’t have to carry all the platform specifics with it. And presumably integrating the hardware RNG can be done once at the OS layer.
After all, amplifiers are always trying to increase the signal/noise, and the basis of the reliability of digital circuits is avoiding the noise. Instead, a circuit can amplify the noise and sample it.