I’m sure much of it violates the rules but my initial inclination is always to browse away, not report.
I'm pretty sure a few explicit Google searches with "site:twitter.com" should pull up plenty.
And I'm not talking softcore, unless my descriptions are way off base.
Granted those aren't necessarily unwittingly, I can usually guess it's going to be like that, but I've definitely "fallen into a rabbit hole" so to speak at other times.
On reddit, if you're not subbed to porn subreddits, you normally wouldn't see it. Though the homepage was still jacked up enough a few days ago that I was seeing softcore stuff on page 1 or 2 with the country set to Mexico.
You'll see a fair degree of NSFW porn if you firehose capture all images, on the "hate speech" front (repeatedly calling disabled, minority, indigenous, queer people names, cyber stalking, etc.) it's reached the point where (for instance) Australia has warned Twitter it will start issuing daily fines of up to $7K AUD [1]
The increased porn & veering into CSAM territory is tailwinding that trend.
[1] https://www.esafety.gov.au/newsroom/media-releases/esafety-d...