Is Technical Analysis useful?

There's no Holy Grail on the market. Also each of us differently percepts market, differently behave and react in various ways for events that occur. Each one investing money in trading should take into account potential losses, as this is something not possible to be avoided.
Trying to answer question from the title of this page, I would say - Technical Analysis can be useful and even profitable. My personal opinion though is that there's need to use it differently/in an alternative way when comparing to methods that can be learnt from Internet sources and books. Plus key here is to take a look always on a volume and volume-related indicators.
But it still won't release you from analysing the background to check what's happening on the selected market before you take position! One of biggest mistakes would be to take blindly each signal that our indicators generate.
When speaking about alternative usage of technical analysis, what I meant was to use Divergences, combining signals together to build bigger confidence before opening new position, check the place and context when signals occur and take volume into account (Volume Profile, average volume + spikes, Money Flow Indicator, Volume Weighted Average Price - VWAP etc.).