I wonder if their problem is that the majority of their traffic is unregistered users looking at NSFW subreddits. So they may not actually have that many users they could monetize in the first place.
As for an official paid feature: as soon as they start collecting money for video related features, the video creators will start circling for their cut of the revenue.
Not anymore, they've banned it.
NSFW content can work perfectly fine to get users on the platform, even if it can't be monetized.