But I have never found any technical indicator which provides a quantifiable edge for entries, or any other part of implementing a trade.
Maybe a moving average to highlight trend, momentum etc, but entries, management and exits (and therefore the trade) are based on price action.
It is my belief, and my experience, that most traders have entirely the wrong concept and expectation of technical indicators.
Is it likely that indicators which are popular, and free on trading platforms, can provide an edge if everybody else is using the same thing in the same way? In my opinion, it is unlikely. If it was that simple, the large trading entities, the funds and institutions would be trading this way. Everybody would. An edge in trading needs to give you a viewpoint which is different from the majority.
As a simple, basic example, which I have given before, think of finding a price pattern which shows clearly that traders who took a rational, logical action yesterday are today trapped on the wrong side of the market. It is reasonable to expect that those traders will/must do something about their predicament. And it is then possible to envisage what action that might be. Now you have something that provides a higher probability of one thing happening than another.
That is a simple example of an edge which, if identified correctly, will play out in your favor over a large enough number of trades. All this may take place in the vicinity of a technical indicator, but the technical indicator is not the cause.