Actually, I think many apps don't even require Tauri, Electron etc. They can use localhost:unique port and open the ui in browser when we click from tray?
This is exactly what Tauri does: unlike Electron it relies on the system web engine.
Do it uses extra memory? In browser I can open ui in multiple tabs. But, I suspect tauri creates another browser window with different process which consume similar memory that we see in electron.