Fibonacci retracement levels are consistent. The issue is that most people have not developed the skill as to how to interpret what it is they are observing and/or, how to even use the tools correctly. Not a slam against anyone - just a fact.
Anyone who has taken the time to backtest will see that there are consistencies between Fib retracements/extensions and the size/length of a wave. Yes, there are market aberrations, but the consistency of levels reached is there.
Fibonacci patterns are not just some "made up" methodology. The entire universe is based upon the Golden Mean ratio of 618 in the cycle of formation and movement of matter. The formation of market waves as a response to repeatedly confirmed human emotional response patterns has been well established and proven. Elliott wave theory is also based on this principle.
However, again, most people do not understand how to identify wave formations and account for aberrations that occur (even the aberrations themselves follow Fibonacci and Elliott principles. (One can observe these aberrations in nature in what are referred to as "deformities")
Experienced and skilled traders understand that any indicator is simply a means to confirm what is being observed. Fibonacci retracement and extention targets used in conjunction with candle formations and Elliott wave rules and perhaps a calibrated oscillator will increase the potential of making a winning trade decision.
Some traders say they don't bother with using Fibonacci tools. But that is only because they have, by whatever means, developed an "eye" to spot the natural Fibonacci retracement levels and Wave patterns without using them.