It's all over the place on social media. What gives you the sense that is has disappeared?
That's a far cry from the scientific, serious, mainstream approach that was common for those topics 120 years ago.
The practitioners (i.e., not academics) back then (Milton Erickson, Dave Elman, Henry Munro, and many others) were much more knowledgeable and interested in studying the phenomena they were investigating and applying than are today's practitioners, who seem instead much more interested in fooling people and making easy money than in advancing the discipline and making new breakthroughs.
I just pulled out of my library the book "Suggestive Therapeutics" by Munro, and it is, however naive in parts, a serious and passionate investigation of hypnotic phenomena. It is evident, even just by reading the text, that these were serious people who thought they could make a huge difference in the lives of others.
Can we say the same about today's practitioners?
This just sound like you need to follow better social media circles. There's a bourgeoning scene around people such as Gwern, Nick Cammarata, Aella with a lot of high-quality discourse on the topics you mention.