The biggest problem with DDR3 is that the last (consumer) boards/CPUs that could use it are really, REALLY old. 5th-gen Intel or AM3 AMD. Which means you're looking at a full decade old, at the newest. These boards also probably can't do more than 32GB.
Now, I suppose if you only need 32GB RAM and a CPU that's pathetic by modern standards, then this is a viable path. But that's going to be a very small group of people.

Most (US) companies don't consider the US government to be a significant risk to their business, partly because they're already subject to it.
They also commonly believe that Microsoft can secure these keys more effectively than they could do so in-house. And they're probably right.
Now, it's an entirely different story for any companies not subject to US law.