98% of the time I prefer YouTube (With AdBlock on of course). YouTube in most cases has the actual music videos, and a lot more adventurous (video) content because they can host remixes, which are so much more entertaining than just a bunch of album covers. Spotify also does nothing to promote and pay independent artists, they actually charge most independent musicians (even the ones not making profit) to be displayed on their platform rather than paying royalties, which is a pretty much giant ponzi scheme. YouTube does not pay greatly either in most cases, but it will occasionally promote artists better, and it allows content to be shared on other sites far beyond Spotify's controlling and restrictive attitude towards music content (they don't even really own nor make) hosted on their platform.

Spotify's UI is wonky and lacks visual appeal at most times for me. Having to frequently go back to the app to control or change what is playing is quite annoying, it really only needs to be a small scale floating window, as music player tech really hasn't changed dramatically since winamp. Spotify is not a revolutionary company at all, even Soundcloud (still not great to independent musicians either) has had a more visually appealing layout that values artists and the music content more than Spotify, and they've been that way for decades now.

The Spotify desktop client is based on Chromium Embedded Framework aka CEF (https://bitbucket.org/chromiumembedded/cef/src/master/), which while awfully similar to Electron, is definitely not Electron.