Their servers are so old, even an entirely different architecture emulating x86_64 would still see a performance increase... So there's no OSS argument here - they could even buy a Talos, have no closed firmware, and still see a performance increase with emulation. If they don't care about the firmware, there are plenty of very cheap x86 options which are still more modern.

> Their servers are so old

When I read this, pop culture has trained me to expect an insult, like: “Their servers are so old, they sat next to Ben Franklin in kindergarten.”