Earlier quoted context omitted.
The problem is that Web exists in a sandbox. They can collect data about my usage of their website, full stop (large sites like Facebook and Google get around this, but that's not really telemetry). With desktop there's no way of knowing what's collected with "telemetry"
And that is the problem of using OSes with outdated security model from mainframe era.
You have no idea how much data is collected by an average application on these platforms.
They don’t call it telemetry, they call it “analytics”, but it’s pretty much the same thing: https://www.quora.com/What-is-the-best-platform-for-mobile-a... https://www.templatemonster.com/blog/best-mobile-app-analyti...
Unlike Windows, a lot of parties have access to the collected data: application developers, and also these platforms like localytics/upsight/google/etc.