Maybe I have the wrong impression, but I feel like the author of the original post never wrote anything cross platform that's sufficiently complex (ie, more than a "let's fill out a form and press OK" Qt app).
> The trade-off — and there is a trade-off — is that Electron applications are shite in comparison with proper native applications.
There's nothing inherently electron-specific that makes an app "shite" any more than writing one in Qt would. You can write shit in any language, framework or platform. The day someone invents a system that protects us from our own stupidity will be the day humans become obsolete.
> They fail to integrate with the host platform,
Untrue. You can—if you need to—integrate with the host platform by writing a native node module, however it becomes less cross-platform at this point.
> they are slow, they hog memory and drink power.
Yes web apps use a bit—sometimes considerably, depending on what you do—more memory, and a bit more CPU (and hence bettery),
but they are not perceivably slower, unless you're doing something stupid (in which case the equivalent Qt app would probably suffer in the same way).
> But let's be honest here – there is nothing preventing e.g. Spotify or Slack from building native clients for each platform they support, and I find it difficult to believe that the costs would be prohibitive.
Maybe, maybe not. I think using a cross-platform solution wouldn't be ideal for them (they'd need to either rely on something like Qt, write their own rendering engine, or use something like SFML; all of these are overkill compared to Electron), and the alternative is writing it in different languages for each platform, which would probably inevitably cause the projects to get out of sync in one way or the other over time.