it’s likely an extremely low percentage of users

its not, its actually a pretty high percentage, the conversion rate of pop up email form to static forms in the footer or header are like night and day. Static email sign up forms are lucky to see a 1% conversion. The average pop up conversion rate for emails pop up with incentive (like a discount code) in 2024 was 7%.

If people stopped filling out the pop up forms they would go away, but people still continue to bite so they live on.