IMHO, the statement: "absence of evidence is not evidence of absence" while logically true is not the absolute "get out of jail free" card that many "believers" seem to think it is.
For 80 plus years we've been hearing that any day now, we are going to get the clear and definitive picture or video proving the existence of ETI visiting earth. In the 1950's, only a few people had cameras and they were cumbersome to use quickly, required film, had delays between taking a picture and having results (developing), and were relatively expensive to own and use. By the sixties, many (most) families in the developed world had a camera and film and development costs were within reach. By the 1980's many families had video cameras, but these were typically dragged out only for special occasions. In the 1990's along came digital cameras where cost per image became negligible and initial camera price was also modest. Importantly, the time between snapping a picture and seeing the results was near instantaneous. In the 2000's, digital phones with digital cameras (still and video) came on the scene. Ownership was low at first, but adoption was rapid. Even in less developed countries, most people had access to such a device by the 2010's. Also in the 2010's the cameras in phones improved dramatically to the point where the camera's were better in many respects than the human eye. Digital security cameras came on the scene this decade as well (first Ring doorbell 2014). In the 2020's, there are more digital phone subscriptions than humans on earth. According to the International Telecommunication Union (ITU), there were more than 8.58 billion mobile subscriptions in use worldwide in 2022, while the population crossed the 8 billion mark. Fixed digital cameras (security, doorbells, traffic, etc.) have become ubiquitous. Each of these devices are continuously recording and many have at least a partial view of the sky. The number of images created everyday far exceeds the total of images for many of the decades in the 1950s - 1980s.
I think (again my opinion), that a strong case can be made today that we have enough images or devices showing an absence of evidence of ETI that we are approaching very high-P values of this most likely means there is an absence (of ETI). At the very least, we can state a hypothesis that people's firsthand reports are very likely to be mistaken. We test this by comparing the number of witness reports that seem to indicate an anomaly out of the number of humans on earth and the time they spend looking at the sky versus the number of anomalous images (not LIZ, but actual anomalies) and the number of images of the sky. Given the large number of reported sightings versus the low number of good images showing ETI (zero), we can show the null hypotheses (people are not seeing ETI) to be true at very high p values (3 sigma+?).
Now of course it is "possible" that ETI is here and invisible to all of our cameras and other recording devices, but of course, then they would be invisible to observers as well.
Bottom line, I don't think we need to wait another 20 years to have high confidence that ETI is not on or near Earth. We said something similar 20 years ago, and the sensor coverage of Earth has increased more than I expected in the intervening time. As many commentors have stated, "Time will tell". I think it has told.
