A bit off-topic by me;
As many skeptics completely throw out eyewitness testimony as being unreliable --even from those witnesses who were quite close to the phenomenon / have had corroborating sightings from other witnesses.
You're right that skeptics shouldn't dismiss eyewitness reports out of hand- and I find many reports of UFOs, cryptids, ghosts interesting (and entertaining) even if I don't think they necessarily represent what the claimants believe they do, but in the absence of other evidence they remain eyewitness reports of (arguably) improbable phenomena.
We know that many sightings of UFOs are cases of mistaken identity; that some famous sightings (and reports of meetings with aliens) which UFO enthusiasts and sympathetic authors supported for years have been shown to be hoaxes; some famous cases (Farmington, NM, 1950 and Rendlesham Forest, UK 1980) have clearly grown in the re-telling by some witnesses (when other witnesses maintain nothing
particularly unusual happened); and a small number of high-strangeness reports might be connected to parasomnias or other neurological causes,
see the thread "Alien DNA after sexual encounter",
https://www.metabunk.org/threads/alien-dna-after-sexual-encounter.12070/;
and if IIRC in
Dark White: Aliens, Abductions and the UFO Obsession, Jim Schnabel 1994 (Hamish Hamilton) an Australian woman underwent a "classic" abduction experience while being watched by her concerned friends, she was actually having an epileptic seizure.
But despite the many eyewitness accounts, we don't know if
any are of extraterrestrial craft, or if extraterrestrial craft exist.
Or if intelligent extraterrestrials exist. Or, if ETI does exist, whether we will ever be aware of their existence.
As has been pointed out on other threads, there have been many eyewitness accounts of visitations by religious / cultural figures, and accounts of miracles witnessed by hundreds (if not thousands) of people. Often the experiencers are reportedly amongst the most honest and sober in their community. These phenomena continue into the present, sometimes in developed "Western" countries. I'm not sure we should take them as scientific evidence of direct Divine intervention,
(On Wikipedia see Marian apparition,
https://en.wikipedia.org/wiki/Marian_apparition,
Weeping statue,
https://en.wikipedia.org/wiki/Weeping_statue), but it seems clear that many witnesses firmly believe in the objective, literal reality of their experience.