I don’t necessarily agree with this. It could be true but there’s no reason to believe it has to be true. Humans sent Voyager beyond our solar system while playing Johnny B Goode. Sure, it hasn’t gone light years, but it’s out there with no attempts to avoid detection. We’ve sent electromagnetic communication even farther, perhaps 120 light years away. Proxima Centauri is ~4 light years away and for all we know has habitable planets orbiting it. There are already plans being made for us to explore it. Do you think we will develop that technology and then decide not to explore Proxima Centauri until we can safely determine any and all possible lifeforms present and then further improve our technology to avoid detection? Absolutely not. In the infinite vastness of the universe it seems likely that there are alien species less advanced than us, more advanced than us, and roughly similar to us in both technology and behavior. Whether or not we ever encounter them is obviously debatable, but it‘s illogical to think that every version of intelligent life that could possibly exist is both technologically superior and has the intelligence and self control to withhold their own interstellar exploration until they completely understand human technology and how to hide from us. Maybe they are imperfect creatures as well and maybe their curiosity of other worlds outweighs their caution to interact with another species. Or maybe they don’t even recognize us as living creatures because a blue planet with an oxygen atmosphere appears so different from their own habitat and they aren’t used to observing carbon-based creatures that walk on a solid surface. Or maybe they’ve been watching us for a while but our own technology and detection capabilities have rapidly improved in the past 50 years and it takes them light years to send new stealthier drones here. Or maybe they are exploring thousands of worlds simultaneously and they actually don’t care about us anymore than the average Texan cares about sharks in the Arctic Ocean. There are endless maybes regarding the identity, technology capabilities, and behavior patterns of alien life. It seems foolish to write this off under the assumption that alien technology must be sufficiently superior and aliens must be sufficiently disciplined to avoid us. We don’t know either of those to be remotely true, and even if it’s true for aliens at Alpha Centauri A, it might not be true for aliens at Alpha Centauri B.