As for music streaming and instant messaging, not everyone has/needs Discord, Slack, Teams, or anything like that. If you absolutely need it for work, just whitelist it. No problemo. And, not everyone streams music. I barely used Spotify myself until I got an office job and needed something to fill the boredom.
The issue isn't about stopping Javascript as a whole. The issue is about permissions management. Not every site needs it, so not every site should have it. If you need it to work for a webapp, just enable it.