What can I learn from an instructor that I cannot learn from books, articles, and videos?
This is from the perspective of someone who started using kettlebells when DragonDoor first started selling them, learned from books, videos and trial and error, eventually was certified and recertified as an RKC under Pavel, and has continued to teach and learn through the present time.
IMO, the value of a skilled instructor falls in a few different areas:
--Taking you through a solid teaching progression that builds skill from the ground up. A good instructor will force you to do all the preliminary stuff that most people learning from books and videos skip or rush through because they don't think they need it, or it isn't that important -- the patterning drills that lay the foundation for good technique.
--Recognizing technique flaws, giving immediate feedback, and having a toolbox of cues and drills to fix them.
--Having enough experience and reps in the bank to develop some insight into the INTERNAL technique -- all the subtleties of intention and execution that are not always obvious outwardly, but can make a big difference in power, efficiency and safety.
--Generally shortening the learning curve, steering you clear of mistakes before they happen, and eliminating the need for a lot of trial and error (but not eliminating it completely; IMO, mindful practice always involves trial and error).
--In many cases, compensating for your poor reading comprehension, listening, and observational skills, and inaccurate self-assessment.
If you are one of the rare people who generally can watch someone do a technique and immediately pick it up yourself, then the value of personal instruction is a little less. However, in my experience this skill is pretty rare, even among very good athletes -- and even great athletes benefit from coaching.
CAN you learn from books/articles/videos? In many cases yes, but it's the harder way.
Can YOU learn from books/articles/videos? Maybe, but it's the harder way.
BTW, from all accounts a user course is a great alternative to individual instruction. The instructors are usually excellent and experienced, there are usually multiple instructors so you get insights from more than one perspective, there is usually a lot of individual attention anyway, you will go through a well-proven teaching progression, and the energy of a group can be very powerful.
Hope this helps.