Nicely put! 
The difficulty is also in identifying which fundamental factors are currently predominent in driving prices. These factors are not just the economic conditions in a currency’s home nation. They are manyfold and often even contrary in their impact on a currency. The obvious example is the USD which is a global currency and not just a USA domestic currency.
The USD value may be simultaneously affected by a miriad of different forces often pulling in opposite directions. Some examples might be current Fed/Govt policies, changing volumes of global commerce priced in dollars, investment portfolio movements of funds into/out of commodities, Int’l companies creating/moving production units around the globe chasing after cheaper labour cost, decisions on whether or not to repatriate profits, etc, etc.
Although these fundamental activities are what drive the price, the problem is exacerbated by the fact that no one can possibly know what is the net effect of all these various factors at the present time or in the future or with respect to factors affecting other currencies. We can only analyse the recent and not-so-recent past and extrapolate into the future.
FA and TA are both looking at the same thing: Price - where it is, where it was, and where it might be going next. But the difference is that the fundamentals collectively drive the price movements whereas technical analysis simply watches the cumulative impact of all the fundamentals.
A currency pair is a bit like the big motorways that ring many big cities. They are filled with traffic going in both directions. No one knows all the individual (fundamental) reasons why each and every vehicle is there at any one time or why it is going in a particular direction but there are factors such as rush hour that can be identified as collectively significant and predictable in their impact. On the other hand, technical analysis is more like just watching, monitoring and measuring the motorway traffic flows through CCTV and deriving conclusions when traffic flows are most dense and in which directions - without actually needing to know why (although knowing that is a big benefit).
In essence, technical analysis should not have any driving or controlling impact on prices as it is purely intended to show what is happening now relative to what has happened earlier. But nowadays when TA is so prevalent and so easy to apply through trading platforms and taught by so many sources, we find that many technical “points” are identified by a huge number of traders and concentrated down to even one pip. S&R lines and trend lines are typical examples, even Fibonacci levels and pivots.
This results in a large number of traders entering a market at a similar time and in the same direction and creates a short term surge in price as a result - such as a breakout through a well-identified level. But although the TA may be the cause of this surge, it does not/cannot predict how long it will continue before profit-taking starts and fresh entries dry up. In fact, TA cannot explain why sometimes levels hold and then eventually they do not.
If TA were to be the only force to drive prices then we could imagine that we would eventually become confined within a set of support and resistance levels for the rest of eternity…in fact, since most traders place their orders inside of S&R levels then these levels would gradually move towards each other until price no longer moves at all. …that is, if there were no fundamentals!
