Based on the fact that there hasn't been any known alien encouter during human written history, that we haven't found any artifact of such an event, even in a distant past, that a 100ly radius is really tiny at the scale of the galaxy, that we haven't found any sign of life outside earth, and that anyway, if an alien civ is advanced enough to come here and invade us we can't really hope to do anything againts that, there is indeed no need to spend time worrying about that.
Considering the evolution of computing and technology in general in the last 50 years would you consider the two things to be remotely comparable?
Neither have we experienced a true AI, and none of the gains in the last 50 years have brought us anything near it, only more advanced computing ability and "trick" AI.
We just assume technology will improve exponentially based on an extremely small sample size. Has it never occurred to us that the technology curve may horizontally asymptotic as opposed to exponential?
The ICE was an amazing piece of technology that grew rapidly, from cars to military warplanes, to our lawnmowers. Yet we can not make them much more efficient or powerful without significantly increasing resources and cost. If you judged the potential of the ICE on the growth it had then, we'd be living in an efficiency utopia now.
Based on the fact that there hasn't been any known AI encouter during human written history, that we haven't found any AI artifact of such an event, even in a distant past, .... , and that anyway, if an AI civ is advanced enough to explode exponentially we can't really hope to do anything againts that, there is indeed no need to spend time worrying about that.
Yet I don't see us losing our heads over the chance of an alien invasion.