Why is there no explanation of what the experimental features in safari actually do?

They are meant for web developers and knowledgeable people who will know how and what to troubleshoot when problems occur.

If you don't know what they are or do, you shouldn't be using them.

This might help:

(Link from site off of Apple.com to helpful page explaining each feature)

https://www.reddit.com/r/iOSBeta/comments/6jrbwq/question_can_someone_explain_sa fari_experimental/