I was expecting the answer to be "code size", since that's Tauri's largest concrete advantage. Instead it's because they want to be able to directly run performance-sensitive Rust code in the main process, and because Tauri has a built-in library for spawning sidecar processes that's slightly higher-level than what Electron offers, at least if you want the process-spawning logic to live in the renderer process.

The latter point seems real but kind of minor. For the former, I'm curious whether they considered using napi-rs or neon to call Rust code from within a Node.js process.

TBH no we haven't considered them. Our initial approach is to keep things as simple as possible and have everything performance critical in one language and if possible in the same process (which is not the case for now). Having said that, if we see that there are better alternatives that will make the project easier to maintain and develop, we will apply them.