alt Hacker NewsEmbedded just means ARM 99% of the time and it's cheaper and easier to use native ARM servers (AWS has them cheap) than to make 100% of software cross compile. Some parts of the firmware might need to be cross compiled but those projects are designed to cross compile.
Your target build environment often differs significantly from your server environment, so you end up needing a different toolchain and all of the problems that come with cross-compilation anyway. The toolchain and ABI settings that produce small, battery or instruction cache efficient are usually not you want on servers.