We're more likely to find artifacts from technology-using aliens - self-reproducing (von Neumann) probes - rather than the aliens themselves, or even to recognize and understand their signals against background, if any. Indeed, humans may be just at the technological threshold of building such probes right now, but we're far from any serious discussion of manned interstellar travel, and in fact it may never be biologically feasible. Such objects are likely to be found associated with lower gravity objects, ie the asteroid belt, where they can obtain materials and build more of themselves. The further they are from home, the less likely they are to adhere to some "mission", and the more likely they are to have mutated and been selected merely for fecundity (reproductive ability.) Therefore it's not obvious that they would be particularly interested in finding other examples of intelligence. They could very well be much more interested in finding other von Neumann probes, and humans might therefore not be the most interesting thing in the solar system to them. If this is the situation that obtains, this resolves a contradiction: other technology-using species have indeed appeared before us, but there's little evidence of them here.
If the von Neumann probes are built from metal, and one planet over the last few centuries suddenly has large metal objects moving around its surface (ships) and smaller metal objects moving much faster through the atmosphere - then THOSE might be interesting. You might expect the probes to be especially interested in locations with lots of ship and air traffic, and especially the ones with the fastest air-objects, especially if the fast air-objects come and go from the large metal objects on the surface. It's been observed separately by other writers that, from the standpoint of an off-world but in-solar-system alien observer of Earth's behavior in terms of natural processes, the appearance of metal objects in the atmosphere and then suddenly in orbit is the most interesting phenomenon that has appeared here for many millions of years at least.
The fact that it's US Navy aviators who have reported many of the UAP sightings is obviously relevant. Given that the reported observations are made by multiple modalities (naked eye, radar, thermal) and official US agency reports describe as likely mostly physical objects, it's unlikely these are glitches: that is to say, either they're real, or they're made up, possible as sort of intelligence or misinformation operation that we civilians are caught in. But if it's real, two questions are important to the hypothesis.
First: is there really a higher rate of UAP sightings around US Navy aviation areas (as there seems to be so far, with sightings concentrated around San Diego and Virginia Beach) or is this just bias because there are more instruments and observers there? Such is the frequency of these events according to the reports that a relatively low-budget operation with some weather balloons over a low-traffic area could move the needle on whether naval air stations are "enriched" for these objects. (If it does not make any such observations, it would suggest either it's a misinformation campaign, or they're real but concentrated around naval air stations.) Related: do JFK or LAX have similar sightings? Or Heathrow? Narita?
Second: is it really an American (or mostly American) problem? Is the pattern repeated around the world at other countries' naval air stations? China or Russia might not be interested in sharing this kind of information, but NATO allies might be. That said, if an unfriendly country discloses it is seeing the same thing, and it has no explanation, then it's much more likely that these objects are real, and at least are not human-created phenomena.
Holy Crap, the Rise of Skywalker Comic is Finally Coming Out
47 minutes ago