VSCode is generally considered to be the canonical example of an Electron app well optimized. They have put a significant amount of work (much moreso than your average company producing an Electron app) into making it very responsive. All you have to do is use Slack or Discord or Atom or Skype and you'll quickly understand why people hate on the performance.

Spotify is a good example of an application that doesn't use Electron (though it uses a similar framework) and still manages to be incredibly slow and bloated. As are most websites. So the problem might not be that Electron is slow... it might just be that the web in general is really slow unless you work extra hard.