They should, but they don't. Teachers make a difference. I'm at a mediocre university and watching MIT lectures has made me realize I'm missing out on literally mountains of knowledge. Never mind the qualification process, spending several years with intelligent people (both students and faculty) makes a huge difference.
Keep in mind that any videos you're seeing are out there because they're mostly very good examples of lectures. Any large research university has lots of classes with very poor lectures. Not to say that the material isn't in depth and peer/TA interactions aren't valuable but don't assume YouTube and OCW are representative of lecture quality.
They should, but they don't. Teachers make a difference. I'm at a mediocre university and watching MIT lectures has made me realize I'm missing out on literally mountains of knowledge. Never mind the qualification process, spending several years with intelligent people (both students and faculty) makes a huge difference.