In principle, there is no reason why Electron must be so memory inefficient, right? We could optimize it in a way that it only loads resources it really needs. So in case of a video chat app, it would need video, audio, web RTC, a bit of HTML and JS. That should be possible to fit in a few MB of RAM. Only because Electron supports much more doesn't mean it must take so much memory.
Maybe it would make sense that we just focus on optimizing Electron for this case. That might take a bit of effort, but that effort might be worth it.
