Just imagine if all of us knows how to use RSI and MACD. We all know when it is overbought or oversold. Therefore, we already know as well when it is good to enter and exit in market. Since we all knew about, RSI is not a good indicator anymore and many of us will find a new indicator that will provide us more details than the latter one.
Now, many Trading Gurus are teaching the best strategy to use. Wherein fact, strategies are becoming obsolete as time goes by. If you are new in trading world, definitely you will be eaten by those traders who know a lot in trading.
This is because there is also other things than the chart that decides the movements of bitcoin. Like lets say it looks oversold, and it will have a correction and it should go up right? Then something happens like FTX and it goes down even more. This doesn't mean that RSI is bad, doesn't mean it wasn't oversold, it just means that you happened to bought it at wrong time and it will get better with time if you be patient.