Just an opinion based on many years of observing the world around me.
The causative events of earthquakes are many and varied. Some of them (perhaps a great deal of them) manifest geophysical symptoms.
To ignore a particular "effect" just because it didn't work the second time is to ignore the success of the first.
The quest for a single datum which perfectly detects an imminint earthquake is a fallacy. Too many people on both sides of the fence act in the manner that since there isn't a single "formula" to follow, then any theory is invald.

Some people experience physical symptoms (vertigo, tones, aches, etc.) which can, with some semblence of accuracy, predict a quake.

Some people (such as myself)have been doing research into geomagnetism, RF emissions, as well as ULF signal detection. Again, with a certain amount of accuracy.

Where I have had the most success has been by reading the current data from a variety of sources, and looking for overlapping information that confirms the others.
I have come to the conclusion that far too many people are fighting amongst themselves as to who is right, with the debunkers waiting in the wings to pick off the weaker ones.
How about we all compare notes instead of making bonfires of each other's notes.
Just my opinion, nothing more.