You've missed the point of the comment that you've replied to. There's a well known adverse selection effect because the people who would pay for no ads are exactly the people who you most want to be able to serve ads to: people with lots of disposable income, and people who are power users who see the most ads.

As a result the actual amount that they would need to charge for an ad-free version is higher than the average revenue per user, possibly significantly so.

edit: you can look at YouTube premium for an example of this in practice. It's $16/mo for no ads. That's around 2-3x or more what their revenue per user is.