- Polyglot; you can write plugins (in this case Bazel rules) in "any" language, and the component model is easily the best system ever created for cross-language interoperability.

- Ecosystem; tooling is still generally immature, but you'd be surprised how much buy-in there is. Web apps are a huge incentive for language developers to support it, and Wasm now runs in a lot of places besides the browser too. Envoy and Istio support Wasm plugins. So does Postgres. So does neovim.

- Component interfaces are richly typed. You get things like lists, structs, "resources" (aka objects with instance methods), etc. all supported idiomatically in whichever language you're using and these can be used across language boundaries. Even between GC and non-GC languages. Even with Rust's ownership model.

- Plugins are fully sandboxed, so a host can allow plugins to have things like `while` loops while enforcing runtime limits on a per-instruction basis. It also means Bazel doesn't have to invent it's own bespoke sandboxing solutions for every supported platform, as it does today. And Wasm is designed to handle untrusted Web code, so there are tons of security guarantees.

- Performance is already really good, and there's every reason to believe it will get better. Again, Browser support is big here. The things the Chrome team did to optimize V8 are pretty incredible, and they're now turning their attention to Wasm in a big way.

[1]: https://component-model.bytecodealliance.org/design/why-comp...