Parapsychology research is at the same stage as electricity was for most of history
An analogy I have often used in speaking about this problem is that parapsychology today is where the science of electricity was for most of mankind’s history. You had two electrical phenomena, lightning and weak static effects. Lightning flashes were spectacular and had great effects; unfortunately, any particular lightning flash occurred unpredictably and was over in an instant, making study difficult. You also had the fact that a piece of amber, rubbed with fur, would sometimes pick up a feather. It was a very weak and erratic force, it couldn’t do much, and it often wouldn’t manifest for non-apparent reasons (which, in retrospect, we can understand as things like relative humidity, etc.). We understood almost nothing about electricity with these two effects for most of our history.
Then the battery was invented. It couldn’t compete with lightning for power and effect, but it was totally predictable and reliable, giving a steady strong flow of the phenomenon of electricity that amber and fur never gave. Now one could set up apparatus and invest energy in study and be amply repaid. Progress has been enormous. In parapsychology we have our lightning: spontaneous phenomena, temperamental psychics, spectacular experiments that don’t repeat. We have our amber: one out of three experiments showing statistically significant, but practically negligible, ESP effects. We need our parapsychological battery.