Assuming that physical inspection leg work+analysis is part of a full 3% commission realtor's responsibilities, I can see that full 3% being valuable to certain time constrained buyers.
However given how rare a house purchase is, I would bet that a large number of full commission buyers arn't aware nor getting the full attention of their realtor.
On the sell side, I really don't see the benefit of a full commission realtor. I did a FSBO before, which is on the opposite extreme. Again I think a discount listing agent like Redfin makes a lot of sense.
I actually wonder why Redfin isn't as popular. I assume due to the aggressive social marketing realators do, and the hand-holding they do during the the high stakes process.