Here are some examples which I consider valuable from top to bottom and in that order:
Educational Content = Tutorials, Breakdowns, Video Essays, Reviews, Advice, Tips, Tricks, Step by Step; topics about philosophy, maths, physics, history, science, science news, geology, sociology, financial (plenty of that already), language, children's education, health, sport, health, beauty, hobbies, how to do, etc
Creative Entertainment = Stories, Art, Movies, Short films, Music, Poetry, Creativity, Animations, Cartoons, Skits, Humour, Standup, Theatre, etc
Revisional/Entertainment Content = Top 10 information videos, Opinions, Entertainment Feedback, Entertainment Breakdowns, Entertainment Video Essays, Fan Theories, Fan Fiction, Popular Media Feedback, Entertainment Education, Entertainment News, etc
Topical Vlogging: blogs and vlogs about artists, workers, teachers, politicians, entrepreneurs, and other topics about work and actions people do - not general lives. Make blogging more topical and useful.
Life/Sport/Fails/Exercise physical evidence of surfing, skydiving, falling, parkcore, exercise, yoga, dancing, travel, relationships, cooking, eating, unboxing, interviews, etc.
Here is how it basically works:
Needs
Solutions
Cycle
Cycle repeats. Value increases - due to more valuable content available and more social interactions around the new content.
In summery, users gain value for the time they invest into the platform consuming content. Creators gain value for the content they produce. Content is what ultimately drives the value of Steem - and the Witnessess (or nodes) and other Steem platforms are the bridges between a User/Creator and the home of the central value driver: Content.
More content will drive more users/creators to create more value for the Steem platform by making new content and interacting more. And that is how Steem increases value - via Content.