Technical analysis is not a panacea and it will not always give you 100% probability for any of the trades.
+1 here, but overall, technical analysis is always important. You rather trade and lost with learning than losing your money in vain.
Technical analysis is one of the best methods to trade, about the market. You should also to consider some things, like candlesticks pattern, support and resistance, using multiple timeframes and some indicators (bonus).
Technical analysis is not 100% effective but at the same time the only other option as you state is to trade blind, at least with technical analysis even when you lose you can learn from the market and make some breakthrough that allows you to reduce the number of times you lose or at least reduce the amount of money you lose on each trade.
But if you are trading without those tools then you learn nothing out of the market which means there is no possible improvement to be made, and this means that you will keep repeating the same mistakes over and over again.