Good question, it’s actually using the native webview component that the target OS already has installed. Electron bundles chromium in each of its compiled apps.

Since tauri isn’t running a whole browser to do its job it can typically do the same work faster. The trade off, of course, is that you need to be familiar with Rust code, but their dev team already is so that should be fine! If they have any hard dependencies on Node’s libraries it could be an issue though.