I disagree that Spotify is a good Electron app (and I've never used Slack so I can't comment on that). I run Spotify on my work computer (Windows) and at home on my Mac and it's extremely resource heavy on both of them, and I often get various weird issues. It's the primary reason I've been moving back iTunes a bit, actually. I never knew it was Electron until now, and I think that explains why I've always hated the Spotify programs on both platforms I've used it on.