[user5994461]

Go is meant for distributed systems. All these companies, and generally speaking a lot of infrastructure thing is in that domain. They use the right tool for the job.

[MichaelGG]

Can you elaborate on why Go the language is "meant for" distributed systems?

[mseepgood]

It has been explained on multiple occasions by the language designers what they meant it for, e.g. https://talks.golang.org/2012/splash.article