That's the amount of code in their repo which covers a lot more than web application servers.

This is an unnecessary tangent though, as I've said throughout this discussions, there's extreme cases and no doubt Google is likely one of them. But we're talking about common use case, to which I still haven't seen any evidences that GC pauses are a deliberating factor.

You may already be familiar with this and are specifically concerned with GC. However, for what it's worth, it's not just the absence of garbage collection that makes languages like Rust and C faster. A huge piece of their performance is the level of control that they offer over types' layout in memory and where things get stored. Rust's preference for stack allocations and the absence of a mandatory per-Object size overhead (a la Java) really allow it to shine.