There are definitely benefits that are larger than just mentoring or bouncing ideas. Often, the sum is actually greater than the individual parts, as fewer mistakes get made and more fruitful paths get explored earlier/faster.
I often go on remote calls with people and our task is to implement something while also training the person or giving tips on how to do it in the future while answering any questions they have in real time (related or not).
So it's more of a 1 on 1 teaching gig for an hour or 2. Not 8 hours of pair programming every day full time.