In the case of SPA and Electron apps, we have a platform used against its intended purpose and the companies doing the platform, paying for its R&D, simply don'

In the case of SPA and Electron apps, we have a platform used against its intended purpose and the companies doing the platform, paying for its R&D, simply don't care to optimize it for that side scenario. Downloading an entire site is an existing strategy, what SPA means (single page application) and these are often terrible UX. You wait a lot for it to load, then it's clunky and the moment you navigate away by clicking a link, you lose a ton of your app state.