What it would do is put a price floor on content. People's willingness to pay, say, $5 instead of $1 for a piece of content is a strong filter, I'm pretty sure low-quality content that's purely CTA wouldn't survive.

Why do you need state enforcement for such a filter? If you only want to see content that the author is asking $5+ for, that's a very simple filter to implement for any website that sells content (and many of them do just that).

The problem is that a lot of potentially viable content falls by default into the marginally-profitable category, where the small amount of utility they provide to the end-user is offset by the incessant user-monetization impulse.

A price floor splits these marginal works into three categories: those that become free, those that die off, those that become viable at high margins. This seems to be a pretty great outcome for consumers.