I'd prefer to speak about "evidence in support of/against" rather than "facts", which often conceals a presuming-the-consequent kind of fallacy.
> denial of science
Whether "science" is believed or denied by any particular person has no effect on whether or not extraterrestrial intelligence has or is visiting earth.
Demanding that "science" be believed is un-scientific. I am not drawing an equivalence between science and religion here, but pointing out that your argument is a super hand-wavey appeal to an inviolable "gospel". I'm old enough to remember when a theory like intra-galactic panspermia was regarded like canals-on-Mars.
In my view, ETI theories are lacking any credible evidence and this makes me sad.
And the facts are just ... released. It's the interpretation of the observations that are disputed. And unless you think they are all fake, the explanations that do not involve alien tech are non-trivial to say the least.
I'm not sure why you'd think there is any shared causal structure with flat earthers at all.
Similarly the absence of a conspiracy of freemasons running something does not inhibit the existence of a conspiracy of Taylor Swift fans running it in any possible way. But I think any objective assessment of whether the Swiftie conspiracy is likely to be real or not should probably take into account the possibility people positing Swiftie conspiracies have been influenced more by well established tropes about freemasons and Jews, and if the alternate hypothesis that a common human failure mode involves positing the idea groups they distrust secretly conspire to achieve unrelated outcome they dislike is well supported and the claim of an actual Swiftie conspiracy isn't...
The only thing that cuts against this is that if I was an intelligent extraterrestrial wishing to remain secret at a time of widespread interest in the possibility of extraterrestrials, I'd probably actively select the sort of people that might discredit the existence of UFOs by pattern matching all sorts of rubbish to reveal myself to.
I've read claims that the Cold War-era US Gov employed exactly this strategy on the people camping out along the fence at sites like Area 51, taking pictures of advanced aircraft under development. I.e., they actually took some people down into the basement and showed them "alien bodies" to confuse the Soviets.
