Not lighter weight than a website because it is a website. The only advantages are you can ship parts of your app as native code, and you aren't constrained by the browser permission model.
This kind of makes it way more lightweight but only in some situations (obv. heavily depending on the functionality of the app).
I used tauri so I could easily make that cross-platform toolbar app.
Some menu items spawn a webview (things like settings), everything else is in Rust.