NVIDIA's licensing. Note that the 3060/3070 is a "GeForce" whereas a 4000 is a "Quadro". Then look at the GeForce driver EULA: https://www.nvidia.com/content/DriverDownloads/licence.php?l...

> No Datacenter Deployment. The SOFTWARE is not licensed for datacenter deployment, except that blockchain processing in a datacenter is permitted.

I could never figure out why they allowed blockchain processing, given how wasteful much of it was and how it impacted card supply for years, but there you go.