I think the overall sentiment with this post is sound, but arenas aren't the answer to Go's performance challenges. From my perspective, possibly in an effort to keep the language simple, Go's designers didn't care about performance. 'let the GC handle it' was the philosophy and as a result you see poor design choices all the way through the standard library. And the abstracting everything through interfaces then compounds the issue because the escape compiler can't see through the interface. The standard library is just riddled with unnecessary allocations. Just look at the JSON parser for instance and the recent work to improve it.

There is some interesting proposals on short term allocations, being able to specify that a local allocation will not leak.

Most recently, I've been fighting with the ChaCha20-Poly1305 implementation because someone in their 'wisdom' added a requirement for contiguous memory for the implementation, including extra space for a tag. Both ChaCha20 and Poly1305 are streaming algorithms, but the go authors decide 'you cannot be trusted' - here's a safe one-shot interface for you to use.

Go really needs a complete overhaul of their Standard Library to fix this, but I can't see this ever getting traction due to the focus on not breaking anything.

Go really is a great language, but should include performance / minimise the GC burden as a key design consideration for it's APIs.