I think its useful, when Im start trading I only use if Im get profit just sell them, but sometime when I sell them the price going up again. Then Im just learn just one TA and applied to the chart its can help me when the time to buy and sell although is not 100% true but its really help. I think it is an advantageous characteristic to possess because it allows a person to decide more logically and based on facts
Technical analysis is still better than not even having any analysis to do at all. With it, you can at least still be able to know how to play safe in the market most of the time. Some of us may have had a bad time with TA, but this does not mean it does not still work 100% of the time.
Most times, you will just have to stick with your own smartness when playing the market and see how things turn out and not completely rely on technical analysis. Because no tool will be versatile enough to read the psychology of traders. Yes, what most traders prefer that alone decides market directions.