It is really hard to imagine for us /humans/, that somebody may not pay attention on us and our efforts!
The universe does not have to live up to human expectations
. The universe is 14 billion years old. The Earth is 4 billion. The oldest hominins are 2 million years old. Homo sapiens have been around for perhaps 400 thousand years. We've only developed radio technology in the last 150 years; the first radio waves haven't even gone that far yet. (Btw, the first broadcast they might get would be of Hitler, iinm).
There had to be a lot of accidents for all the conditions necessary for life to start on Earth. Among the trillions of stars with planets in a zone that "might" be favorable for human life, there's no way to predict that human-like life would emerge or evolve there. There is a probability, of course. But if there are --say-- millions of planets in the universe with human like life -or simply intelligent life interested in space travel-- and all or some of them reached the same tech capabilities that we have, they sure haven't bothered to make themselves obviously known.
The faces on the buildings at Puma look like humans who already lived there. UFO abductees say that the aliens don't look human at all. Guys like Van Daniken talk about proof of alien arrivals on all the continents, and they're all ancient. There's no explanation why modern aliens aren't building monuments today, or why beings with the capability of traveling at or near the speed of light thousands of years ago would bother or need to build anything in stone, if they wanted to stay.
They'd probably have mastered the use of electricity. They'd have air conditioning and heating that would at least be as modern as ours are today. I think if we found alien stuff it would be far advanced to what we have now, not more advanced compared to Neolithic civilizations.
Anyway, another "accident" in human history is that we've survived this long and haven't destroyed ourselves or been destroyed by some natural disaster. That is true for all the other possible places in the universe that may contain life (at the biological level, not even human life). Maybe it's true that extraterrestrials escaped from their dying planet and came here. But, it's unlikely that they were hominins that evolved into homo sapiens. That would be more akin to a creationist view, which would still have to explain all those other million year fossils.
Whether people accept that aliens are angels and that UFOs are extra-celestial beings is up to them. Maybe aliens and angels co-exist. Otoh, we might be the first species to achieve this level of intelligence and technological ability. In which case, maybe our future is to become the "ancient aliens" on some other planet outside our solar system. Though, because of Einstein's time dilation, if someone goes to another solar system, the Earth and the people on it will not be the same when he returns. That's equally true for all space travelers, and it might be why some advanced civilizations might decide to stay home.
"A man is rich when he has time and freewill. How he chooses to invest both will determine the return on his investment."