It's probably a political point, but I think your comparison over sells how inconvenient it is for someone to geoblock one small country and the headache if anything did happen. It's not much more effort than doing nothing really?

And clearly users in the UK can find their own way to read it if they like, so the cost is also small there.

the culture section of this writeup links to explicitly adult/erotic content in the footnotes and discusses 'adult themes' directly. his caution seems reasonable.

>or excessively paranoid.

Have you even read the shit politicians are either pulling or trying to these days? There is no amount of paranoia that is too little when talking about things like cross national prosecution, laws regarding users not considered adults, and age verification.