In that case I misunderstood you. Sure, we can’t always know all tracking details of closed source software, or even open source software with telemetry or some other tracking enabled.

The developer could be using harvested data for monetization. Or not. That’s a bit too speculative and borderline conspiratorial to be discussing.

I released free software myself, my friends have done the same - without any user tracking or ads. So anecdotally I can tell with confidence that free software does exist. Is all free software really free (as in not monetized by the developer in some hidden way)? No, not all.