You'd still have extremely biased data - people who blindly click OK on every pop up are not representative of your typical user; people who get nightmares after hearing the word "telemetry" and will gather the pitchforks if they hear any hint of will always refuse, but depending on your app, might be your typical user (e.g. for self-hosted picture sync and catalogue, who is the target audience - people who don't trust Apple/Google/Amazon/Dropbox to store their images privately)