I think choosing a hybrid approach is the way to go here.
The implementation with Electron, as most cases, sucks.
I work with a startup and they have a hybrid app, which binary is 3.5 megabytes [1]. UI is JS/HTML/CSS and is almost the same bundle as the web version [2]
How does the "hybrid approach" differ from Electron and why is it so much smaller? Don't they still need to embed a full browser engine if the UI is all JS and HTML?