Surely there is a more effective way to write an app than to bundle an entire end-of-life browser and Node.js runtime into a 600MB monstrosity.
The Electron Framework.framework it contains is 400+ MB alone. I don't understand where you come up with your 90 MB figure?
Perhaps this file is just the installer and the actual system files are much larger? Or maybe your 400MB figure comes from a bloated install? Just speculating here.