To say AlphaGo or any RL system is learning from self-play is not in the typical understanding of the phrase. It's more akin to evolving with competitions against previous versions of itself, which should count as different instances. As stated on page 38 of 1604.00289.pdf
Between the publication of Silver et al. (2016) and before facing world champion Lee Sedol, AlphaGo was iteratively retrained several times in this way; the basic system always learned from 30 million games, but it played against successively stronger versions of itself, effectively learning from 100 million or more games altogether (Silver, 2016).
In comparison, from that same paper, it was estimated that Sedol could not have played much more than 50,000 games. My own estimate is about 40,000 games.
As for work required to learn, it's irrelevant to point out that one can learn from others. Learning, whether from play, books or study still requires energy spend and work by the learner. Most of the extra work is from study, occasional review with a tutor and discussions with peers--the last more of a meta-step: learning to learn. Accounting for books and some time with tutors will not, I argue, shift the budget much. Especially if you include that any machine playing Go requires overhead of power infrastructure, energy, cooling, networking equipment and occasional maintenance staff. And learning, improvement in architecture, requires searching through and discarding many changes and playing through a cumulative hundreds of millions of games.
The fact that humans have other available highly efficient means of learning is a boon and not a downfall. That's the whole point of getting to AGI. Learning from books and others is akin to learning by Program Synthesis from specifications.
The reason I noted the requirement of other trained professionals for training a human is that those other humans can distill what they have learned over years of play into simple rules. The machine can also use those rules, but the particular machine you are comparing to was specifically trained without any such rules and was required to synthesize them from scratch from historical games and self-play.
The computer can train itself with just records of past games and self-play. The world champion level human cannot. You must account for the difference in training.