I'd suggest that's not the right way to look at it. To a first approximation, "everything" is using an event loop nowadays, in that everything is using the same fundamental primitives to handle and dispatch events. In particular, this includes the Go runtime; run "strace" on a Go network program and you'll see these same calls pop up in the strace.
What this does instead is give a Go program direct access to the event loop. The benefit is that it bypasses all of the stuff that Go wraps around the internal event loop call that allows it to implement the way it offers a thread-like interface for you, and integrates with the channel and concurrency primitives, and maintains your position in the call stack between events, etc. The penalty is... the exact same thing, that you lose all the nice stuff that the Go runtime offers to you to implement the thread-like interface, etc., and are back to a lower-level interface that offers less services.
The performance of the Go runtime is "pretty good", especially by scripting language standards, but if you have sufficiently high performance requirements, you will not want to pay the overhead. The pathological case for all of these nice high-level abstractions is a server that handles a ton of network traffic of some sort and needs to do a little something to every request, maybe just a couple dozen cycle's worth of something, at which point paying what could be a few hundred cycles for all this runtime nice stuff that you're not using becomes a significant performance drain. Most people are not doing things where they can service a network request in a few dozen cycles, and the longer it takes to service a single request the more sense it makes to have a nice runtime layer providing you useful services, as it drops in the percentage of CPU time consumed by your program. For the most part, if you are so much as hitting a database over a network connection, even a local one, in your request, you've already greatly exceeded the amount of time you're paying to the runtime, for instance.
It does seem to me that a lot of people are a bit bedazzled by the top-level stuff that various languages offer, and forget that under the hood, everyone's using the event-based interfaces. What differs between Node and Twisted and all of the dozens or hundreds of other viable wrappers over these calls is the services automatically provided, not whether or not they are "event loops". Go is an event loop at the kernel level. Node is an event loop at the kernel level. Erlang is an event loop at the kernel level. They aren't all the same, but "event-based" vs. "not event-based" is not the distinction; it's a question of what they lay on top of the underlying event loop, not whether they use it. Even pure OS threads are, ultimately, event loops under the hood, just in the kernel rather than the user space.