Watching a pro can really accelerate skill acquisition because it will expose you to high quality ideas that would have been difficult to develop on your own.
Want to get better at Backgammon/Chess/Go? Play a lot of games (at various time controls). Yes. But also watch professional players and read their analyses of games.
Want to get better at programming? Write a lot of programs. Yes. But also read a lot of high quality code written by others.
Want to become a better mathematician? Spend your time mastering mathematical knowledge and techniques. Yes. But also spend some time trying to get in the heads of the masters - learning their patterns of thought at the mathematical and meta-mathematical levels.
The increased accessibility of this kind of content is one of the greatest achievements of the internet.