I remember there used to be an idea floating around of paying pennies for sending email a few years ago. It would combat spam, since it would not be economically viable to send millions of emails. It failed; since it would kill email, no-one wanted to pay and lock access rights to a certain group of people.

Elon is claiming he wants this for combating bots and scraping. Whether true or not, he will realize soon enough though that people will not pay for it. (Perhaps even find out it's not bots, but actual people downvoting him)

(At the same time, it's a bad thing we do not want to pay for good journalism/info, it leads to free ad-riddled sites with shitty click-baity content. The good stuff is behind paywalls, and therefore not available to the general public. This leads to a breeding ground for conspiracy theories. Since those are available for free (they want the message out there) and the actual researched stuff is hidden behind those paywals)