What the movie doesn't say: The Moneyball approach failed in the end
Fast forward to 2011, the Athletics had the lowest attendance in baseball, with an average attendance of 18,232.
The A's last made the playoffs in 2006 and haven't had a winning season since. This is because the approach inspired copycats with more money who learned the value of signing players with a high on-base percentage. By 2004 these players weren't a bargain anymore. The salaries of these patient guys who drew a lot of walks now reflected their contribution to winning games. The market inefficiencies that Billy Beane had exploited ceased to exist.
Bottom line: Moneyball wasn't a long-term winning strategy, at least not for underdogs. Rich teams ended up hiring statisticians too and outbid poor teams for the players they recommended. Money has come to matter more, NOT LESS, in determining the winning percentage of major league teams.