The fact that this thing is open source is entirely irrelevant.

It's quite simple. You don't know what Github is doing privately with this tool running in their backend systems.

I still don't understand the praise and the excitement of telemetry (open or not) at all from engineers.

They may think that they are doing this 'tracing' or whatever that is, when in-fact it is still spying.

Again, can I opt-out of this 'telemetry' on GitHub? If I cannot and I did not agree to this, then this is very troublesome.