I think the Drake Equation is misunderstood.
It’s NOT an equation in the sense that it is solvable.
It’s only an illustration of the various conditions we would need to say without doubt how many extraterrestrial civilizations might exist and our probability of discoveing them.
As our technology advances, we are able to estimate some of the parameters in the equation, such as the number of stars that have planetary systems and the number of those systems capable of supporting life.
Over the last years, great advances have been made in the detection of extraterrestrial planets around stars - when I was growing up, such detection was thought to be impossible.
But astrometry has progressed. It is possible now to detect the *gravitational* effect of a large planet on a star’s motion.
It is also possible to detect the small, small “shadow” of a planet passing in front of a star.
And more recently, the we are able to detect certain chemicals in planet’s atmospheres that indicate the chemicals are formed by living organisms.
So one, by one, we are able to arrive at values for the various components of Drake’s equation. But it will take actual exploration to find the true value of N.
“to boldly go where no man has gone before.”
It’s not a law of nature. It’s more like a way to think about the problem. But it looks like a law of nature, which misleads people.