dev tools and especially libraries must not have telemetry unless absolutely strictly necessary (and even then!).

* Dev tools because you need to be able to trust they don't leak while you're working. Not all sites/locations/customers/projects allow leaks, and it's easier to just blacklist anything that does leak, so you know you can trust your tools, and the same habits, justfiles, etc work everywhere.

* libraries that leak deserve a special kind of hell. You add a library to your project, and now it might be leaking without warning. If a lot of libraries decide to leak, your application is now an unmanageable sieve.

If you do need to run telemetry, make it opt in or end user only. But if you as developer don't even have control then that's the worst.