I looked it up and apparently there is a "$5 sign-up fee", and posts/reactions are not free too:

>To sign up, users must pay a $5 sign-up fee, meant to prevent the creation of spam accounts. Further, users can only post a limited number of “casts” on Farcaster apps, which are tied to packages called storage units. Storage units, which go for $5 a piece, grant a user 5,000 casts, 2,500 reactions, and 2,500 links or photo posts within a one-year period.

(some shady website)

Yeah, that will surely make millions of users to sign up /s

Yeah, I don't get it. Social media sites thrive on interaction. Giving users a reason to hesitate before interacting is going to snuff out a lot of the casual interactions that make a site feel "alive".