"I have a few questions. If these UFO/UAP entities display amazing technical prowess, traversing interstellar distances, demonstrating profound competence, then why are they so incompetent at landing??"
This is a great question! Lots of folks, skeptics and believers have asked this, and even I have pondered it, but I really suspect the question wasn't my own- but was the result of reading skeptic. Or maybe a comedian's routine picking on believers. I am sure I laughed and thought about. That's good use of humor- to make one think. :)
The best answer to this that I have heard came from Richard Dolan. He suggested a comparative analogy with our tech. We have planes, and planes do inevitably crash, due to human and tech issues. There is a statistical rate at which planes crash. The more planes fly, the more likely there will be an incident. Incidents rates have gone down as tech has improved, but it has never been zero. What has gone up is the number of flights. Do you know how many airplanes are in the air in one time? about 9,728 planes carrying 1,270,40- per google search.
Assume for a moment advanced tech is not fail proof. There is likely a statistical incident rate. We don't know the variables- but we can make an assumptions. Like, we could imagine that the number of UFOs flying is obscenely higher than anyone imagined, which has left us with a sampling of crashes. Not luck, just statistically probability that if you fly enough craft or enough missions, you will eventually have a failure. Humans aren't perfect, why would we assume perfectness in aliens.
The other three prominent theories are: humans shot one down and got lucky, they crashed their own craft on purpose to give us access to tech, or one of our technologies inadvertently and adversely affected them. The latter has come up frequently with certain types of radar suspected of influencing their systems, and or nuclear tests adversely affected craft in the area- which correspond with Roswell as nuclear test sites were in New Mexico.
Ultimately, the answer is we don't know. We simply don't know enough about what's going on or the tech to do anything but speculating. I don't think this question is a good foundation for the argument against UFOs, though. Let's say you have the tech to traverse the stars, and you have an incident- incidents will likely be more catastrophic in their failures the further you are from home base. That's definitely true for us. Right now, if we sent people to the moon or Mars, and something went wrong- they're likely just screwed. Apollo 13 crew weren't just lucky- that's evidence for a miracle! I imagine that was the last time all of humanity were single mindedly praying, or wishing another person well.
