This is the morally correct thing to do but it does result in selection bias for any statistics gathered. It's hard to figure out a way to get good data but users rights must be respected.

Somehow, before the wide availability of constantly connected Internet, software got made. Perhaps constantly collecting data on your users is not required after all.

If your competition is collecting user data and you aren't then they have a competitive advantage in understanding where to make investments for future development investments.

It's really best to just kill the arms race and restrict data collection.

You can fight back by exposing how much data the competition collects. I buy devices that collect less data as a choice. Many others do too.

You don't get any meaningful stats from opt-in. Might as well not collect any data at all.