Writing apps for the browser is one thing, I don't particularly like it because it lacks the level of integration native apps have but for performance, it is not that bad. Browsers are well optimized and offer many interesting features out of the box.

For me, the problem is that an Electron app ships with its own browser instead of using the one the system already has.

Another example, mostly in the Linux world, is to use containers with their own subsystems instead of using system libraries. Snap, AppImage and Flatpak do that, especially Snap, which I think is the only one that doesn't support external dependencies.

I understand the appeal, but that's really wasteful.