It's okay. It actually produces the smallest wasm binary size AFAIK. I'm just tired of niche languages already. If I were to go niche why not https://grain-lang.org/ ? It's even a wasm-first lang. Zig is also good and produces small wasm binary. That said, I think Rust/Go is fine.
AssemblyScript seems like a pointless also-ran. Why pick a language with very little support or community for your native code when you could pick Rust or C++? For any substantial app, I think an investment with Rust would be much better than an equal sized investment into AssemblyScript.
I think Rust will be around in 5 years. Will AssemblyScript?