I think it makes sense if you think of Tauri as a "view layer" for rust apps. If you're building a rust GUI app using something like Dioxus, I could easily see wanting to bundle a cross-platform renderer with consistent "quirks", vs having to adapt your frontend to work with all the platform web views.
It has trade offs in terms of memory usage and binary size, but Electron has already conditioned users to expect every todo and chat app to be 500mb on disk and use a gigabyte of ram at idle. In other words, if Electron would make sense for your project, but you want to use rust, this seems like a good fit.