Local server as an ElectronJS alternative

I need to build an app that needs to work offline and be installed on the computer. I know C#, JavaScript, and Python. I feel very comfortable building UI with React but ElectronJS apps are too big, so it is off the table.

I was thinking of this:

Write the core logic of the app as a local server (ASP.NET, Flask, or Express) and a frontend for that. When the user clicks on my app, it automatically starts the local server and opens the frontend on their default browser. When they close the tab, the server will turn off too.

I can't see any reason why this won't work. On the other hand, I have never seen such programs which makes me think that there is something fundamentally wrong with this approach. Why people don't use this instead of Electron?