All I can say is the author babbled on quite a bit without once mentioning the Drake equation.
https://www.space.com/25219-drake-equation.html
The Drake Equation has a garbage in garbage out problem because it does not account variables or the possible existence of only one.
You could make and argument there is no intelligence life on Earth
The salient statement in your reference on the Drake equation:
“The challenge (at least for now) is that astronomers don’t have firm numbers on any of those variables, so any calculation of the Drake Equation remains a rough estimate for now. ‘
Translated into normal English: any predictions resulting from the Drake equation are essentially based on numbers astronomers have pulled out of their posterior orifices.
Truth be told, unless we have some idea of the odds of life developing on an Earth-like planet (and we have no idea of those odds, since we have no idea of the step-by-step mechanisms of going from a promordial soup to a primitive bacterium) it doesn’t matter how many galaxies, stars, earth-like planets exist - we’ll stil have no idea whether life is plentiful or rare - well, not unless ET stops by and says Hi! some day.
The Drake equation is a proposal dependent on conjecture, verified by speculation, and documented by assumptions.