> Apps can't be 100MB on modern displays, because there are literally too many pixels involved.

What? Are you talking about assets? You'd need a considerable amount of very high-res, uncompressed or low-compressed assets to use up 100MB. Not to mention all the software that uses vector icons, which take up a near-zero amount of space in comparison to raster images.

Electron apps always take up a massive amount of space because every separate install is a fully self-contained version of Chromium. No matter how lightweight your app is, Electron will always force a pretty large space overhead.