Here you have simply assumed that the business case for Fuchsia must be externally visible to consumers. Why assume this? The overwhelming majority of Google's software runs on Google's computers and you have never seen it. Perhaps they would consider it a success even if the only role for Fuchsia is in their datacenters. There are abundant reasons why Google would want a non-Linux operating system internally.
When gVisor was released to the public, my conspiracy theory was that the future of Google Container Engine was gonna be gVisor-on-Fuchsia instead of current gVisor-on-Linux. Consumers couldn't tell the difference, gVisor is the one implementing the user-visible "Linux" on both.
(What's visible of Fuchsia doesn't quite support running on "big computers" well enough for that to be true...)
> here are abundant reasons why Google would want a non-Linux operating system internally.
You may be in the right, but I personally don't see no reason for it. Linux is the best supported operating system in the world and Google always has the option to alter the OS if need be.
I do believe Fuchsia is vastly more secure and stabler than Linux, which could be a benefit, but Google isn't exactly being pilfered by miscreants on a daily basis, so that benefit is in doubt.
Google pays for hundreds of engineers working on the Linux kernel, who spend a lot of their time arguing with Linux maintainers about what should or should not be upstreamed, and painstakingly grooming their internal diffs vs upstream. You can imagine why not having to do that would be easier.
