I believe, if not with technical analysis, how else can we determine the direction to buy or sell. at least it helps compared to having to just guess. As far as usage goes, I get premium signals with technical analysis, they are quite accurate, although not 100%, but for me that is enough proof that this is quite accurate and profitable.
You are right, without technical analysis of course we would have made the decision to buy or sell only based on the feelings we have and it would be very unlikely that we would be able to get the profits that we would get, if by using technical analysis we would not be able to get our profits. It is still possible to improve the analysis that we use to be able to gain from the trading that we do.
And it is also because trading is not just guessing what to do next, there should be some basis for our decisions otherwise, we make our trade into a 50/50 result. That is why it was been encouraged for traders not just to live confident of knowing the basics but also to enhance their level of trading knowledge and skill just to meet the satisfying way of trading and make positive results.
Perhaps, there are a lot of trading tools that we need to know, we have to learn them, especially TA.