Users don't like slow and bloated. Given equal choice users prefer small and fast. Of course, they are okay with Spotify client, because there's no native Spotify client with the same functionality. People want to have the service, but don't think that everyone is okay with how this service is packaged.
That is - just because Electron will get faster with some optimization doesn't mean that it's possible to become enough faster while still completely implementing the various web specifications.
Absolutely true. I don't like that the web is so complex there are only a few competing implementations. Still, it's the best we got in terms of platform support.
> doesn't mean that it's possible to become enough faster
Unless you bloat your app with tons of frameworks, I don't think the issue is speed, but size, which is true for web in general. Almost all of that size can be deduplicated (and some big parts even discarded).