Charting is not only useless for Bitcoin but for all asset classes for most of the same reasons. Real traders, not speculators, make their money on spreads and volume. Charting was invented in the 1920's by market makers to generate volume, thus money, from speculators. Why do I know this?
I have worked in and around the markets for over 50 years (yes, I'm old.) I passed my Series 7 at 19, working for a bucket shop while I was in college. After college, I became a securities analyst at a major financial institution. Back then (1974), they sent me to shadow a floor trader on the floor of the NYSE as part of my training.
The trader was Mike Metrinko, the longest-serving trader on the NSYE. Google him. Mike was on the floor since 1928. He explained that the floor specialists knew how to jiggle prices to get the charters to buy or sell. When they had too much inventory of a stock on their books, they would send a buy signal—the same for a sell. The day traders were (and are) basically suckers.