alt Hacker NewsBut arenas have substantial benefits. They may be one of the few remaining reasons to use a low-level (or "systems programming") language in the first place. Most things are tradeoffs, and the question isn't what you're giving up, but whether you're getting the most for what you're paying.
Arenas are also available in languages with automatic memory management, e.g. D, C# and Swift, to use only modern languages as example.
Thus I don't consider that a reason good enough for using Zig, while throwing away the safety from modern languages.