I am not a UFO (topic) fanatic - much less a "conspiracy" fan.
And even though I have seen many... strange things (and I am educated, even highly so - I mention this because it IS relevant), more often than not I,
too, tend to think that unidentified flying objects are state-of-the-art Earth technology.
But I must say, your argument was greatly marred by the following:
How come we didn't have any UFO sightings or alien abduction reports in the last 10,000 years of human civilization until just now (20th
century)? It's because the technology is new, and it wasn't around back then. All documents of UFOs and aliens that date before the 20th century are
lies. If you think aliens are real, then ask yourself this. If you were from a million year old race that has mastered space travel, then would you be
interested in interfering with the affairs of a primitive planet? No, you have much more important things to do then waste time on a primitive planet
that is millions of light years away from your homeworld.
First of all, there is no basis whatsoever for dismissing some of the ancient reports about UFO (in the strict original sense of the abbreviation) as
"lies" or misinterpretations of some natural phenomenon.
People who lived in ancient times were not only much more familiar with nature and its phenomena (regardless of their explanations for them) - meaning
that they observed
it much more than today's "average Joe/Jane" does (and so they knew what was "natural" and what not): we're talking
about people who were able to calculate - pretty accurately! - the circumference of the Earth with the help of no more than a stick and their mind,
basically; people who were able to erect constructions (not only the pyramids) that still to this day baffle architects and other construction
And so, if the good people of medieval Nurnberg (just an example) present me with a picture of a sky full of things that were clearly not stars or
comets or any natural phenomenon we know of, I have no valid reason to doubt them. (Because arrogance
does NOT constitute a valid reason, not
in my view.)
And secondly, it's naive, to say the least, to speculate about the possible reasoning of "aliens" based on exclusively human (=Earthling)
argumentation. I don't know - nor do you - WHO "they" are (IF they "are"); I don't know - nor do you - what they would consider their priorities
In fact, I don't know ANYTHING about them (if they exist) - nor do you.