In short to answer the original question, Elliott Wave and Gann are just two theories. Point and Figure patterns (other than one box reversal) are .... easy to believe in. They are simple and clear. All the classical chart patterns were identified by Schabacker and Gartley, and newer ones...
Trivia question:
How were the markets different from 1980-1999, 2000-2007, and 2008 to present?
Multiple differences among periods. US Treasuries and Stocks used to trend together until 1998, then began moving inversely. Huge Bull Market 80-99, Dollar strong, lots of foreign...