But comparing it with a teacher is complete nonsense. Yes it can be useful but pure in addition of a college based training. Or as a interactive handout after a college. Especially if it gives the ability to give feedback/additional information (like a wiki).

You said:
“I think good digital content could beat a bad instructor.”
Sure, a good runner can outrun a bad/broken car. Or the right ticket win you the lottery.
Why should a teacher only use a white-board to explain the principles of a clutch.
For me, it sounds like cheap commercial arguments.
In my opinion you lacked to mention the biggest con. There is no interaction. You can’t ask a question, you can’t give real-time feedback and you can’t talk about it with a colleague

Though, we live in a fast moving world. And if we want keep up with it, we have to improve the the way of teaching. Cbt’s can be a way to improve it. In addition.
And don’t forget to spend some time/effort to translate and localize the training. There is not something like, one size fits all. Vct’s (Video conference training. I think). Is a nice compromise.

Btw. Most of the cbt’s wbt’s ibt’s where a wast of time. But there is a nice lineup in quality. So, maybe some day…