You need TA for all coins either it's Bitcoin or altcoins in general. Altcoins are mimicking Bitcoin movements but there is what is called dominance. If you notice market movement, there used to be a time Bitcoin will be opening green candles daily and some altcoins will follow but not many of them do that, the once that move most are supported by the actions of fundamental news, that trend will continue until dominance of Bitcoin reduces and then that of altcoins increases, this is when you will have altcoin season that a lot of coins moves rashly, that's the moment of no TA but strictly fundamentals.

However, there are some instances where TA is important, after all the TA has finished their rallies, they will come back to make a retracement, you will need TA this time to know the next move, that's when the support of and resistance of the previous charts becomes important because you can't make new supports if the previous ones doesn't actually exist, you can't know much about a chart of a coin unless you know the previous activity of the coins, this is why you need to trade altcoins.