Our instructor threw together freely available YouTube videos and Wikipedia articles instead of lectures. What should I do?
As a student, you are paying for the tuition (teaching). Teaching is an activity designed to help you learn and acquire new skills. 
Teaching materials (books, slides, video lectures) can be good, bad or ugly, but they are only a (smaller) part of the whole picture. They are not an activity. Arguably, they matter less.

What matters more, in my opinion, is the opportunity to obtain constructive feedback from your tutors. Not the grade for your submissions, but actual analysis of your work, explaining its strength and weaknesses and providing you with some ideas on how to improve and what to work on. Not a general piece of information, but something unique and produced specifically for you. 

I have rarely seen online courses where students have enough personal attention and receive more than just a few lines of personal feedback. Honestly, the situation with many traditionally run courses is largely the same. Being massively oversubscribed and under-staffed, many Departments are not able to provide students with sensible feedback on their work. As a (pathetic) attempt to compensate, they sometimes claim that they provide exclusive teaching materials, which, however, tend often to not really be any better than standard textbooks.

My suggestion is: don't be obsessed with materials you are provided with, but look at whether you're receiving enough attention and personal guidance from your tutors. If you're not getting enough feedback - it is probably time to raise your concerns or maybe even look elsewhere.