Companies used to do this with focus groups and beta testers. Now they outsource the work to their customers, at a high privacy cost.
If client-side telemetry is benign, then it should be fully removable for people who don't want it (Firefox good, Windows 10 bad, web session replay terrible).
> Companies used to do this with focus groups and beta testers.
Even with beta testing, you still run into serious bugs that are completely unknown until the code hits production. There's far more diversity in the runtime environment among non-enthusiast regular users than you'll ever encounter in dedicated test efforts.
If client-side telemetry is benign, then it should be fully removable for people who don't want it (Firefox good, Windows 10 bad, web session replay terrible).