As much as I'm interested in the search for extraterrestrial life, exoplanets and the like, I think the chances of advanced alien visitation are remote at best, as the distances involved are just too great. I've seen a few things I couldn't readily identify, but the more I've investigated over the years, the more likely I think it is that the vast majority of sightings are simple misidentification and/or wishful thinking on behalf of the observer. I can believe there are sometimes niche or secret test vehicles out and about, but I don't think they're reversed engineered alien craft and suchlike. It's a romantic idea, but unlikely. Certainly doesn't hurt Governments to allow that notion to take hold, as it diverts attention from genuine black projects. I suspect many sightings are planted precisely to steer curious minds away from what's actually going on.
What I do find interesting is how popular culture shapes what people think they have seen. Certainly the case with alleged alien encounters that geopolitics and popular culture seem to have a big influence on what is reported. The Cold War generated a lot of reports of "Nordic" type aliens trying to warn us about nuclear annihilation and the like, which then morphed more into environmental messages, before the late 70s saw the rise of the "Grey" alien encounters, being exactly the type depicted in Close Encounters and Whitley Streiber's books. Spin on to the 90s and the X Files and the growth of the internet saw the conspiracy narrative becoming the context in which a lot of sightings were reported. Ufology took a noticeable step into far more paranoid waters (Disclosure Project, Icke etc), where conclusions exist before the investigation, lack of hard evidence is presented as proof of cover ups and everyone seems to be swimming in a sea of their own confirmation bias. Any criticism of objective analysis is very quickly attacked as being "disinformation" and anyone who doesn't continue the conspiracy narrative is smeared as part of the conspiracy. It's all got very, very tribal, which is a shame, as genuine investigation has suffered.