Because Reddit is old and big. Banning it would piss off lots of people.

It's the same reason why Chrome, Safari, Firefox etc can get away with it, despite clearly having accessible NSFW content.

This is the real reason. Notice that there’s no real 4chan app on the App Store, even though it has both SFW and NSFW boards, just like Reddit. Apple will bend their own rules depending on who they’re applying them to, they have zero integrity.

Primary purpose. You can build a web browser that can load porn, but that’s not the raison d’etre of a web browser. Similarly Reddit is far more not porn than porn.

The risk of a porn story and counter-narratives of non-porn utility. Shipping and trucking has a risk of a trafficking story, but it has much weightier counter-narratives of salient utility.

reddit would likely get rejected by the app in today's enforcement environment. discord was recently forced to disable nsfw channels in the ios client

Number of users

Loudness of users