I think it's just because Downdetector is getting tons of traffic which makes it think people are having more issues than usual with virtually everything. I haven't heard any actual people say Spotify, Twitter, or Twitch are down.
Doesn’t Downdetector count only users who click on “I have a problem with [service]”? It would seem dumb if all charts moved together any time there is a major outage of a single service.
I just ran into that issue trying to download a few different apps an hour ago but figured it was my phone. Something is definitely up, too much of a coincidence for these issues to be happening at the same time
Down detector scraps sites (twitter and reddit) for 'website.com down' and marks a spike