TL;DR - UFOs are real in the sense that there are Unidentified Flying Objects (also called UAPs, for Unidentified Aerial Phenomena) for which we as yet do not have any explanation. While a vast majority of these objects remain unexplainable, that doesn't necessarily mean that they are extraterrestrial in origin. They could be anything from tricks of the light combined with technological sensor errors to atmospheric phenomena we don't understand yet. However, the absence of evidence is not evidence of absence, so we can't fully rule out extraterrestrial origins; it's still a possibility.

• The US intelligence community recently released a report of its preliminary investigations on UAPs. The report was inconclusive overall, coming up with an explanation for only one of the 144 sightings in consideration. Proposed categories of explanation for the remaining unidentified phenomena are: airborne clutter, natural atmospheric phenomena, secret US government projects, advanced foreign adversary technology, or the catchall "other". This last category could include extraterrestrial phenomena.
• The astrophysicist Neil deGrasse Tyson has explained that he remains skeptical of the UAPs, for the reason that "not knowing what it is" does not "count as evidence for knowing what it is." He has further said that he believes any of part of the sensor technology could be running errors, accounting for some of the videos/sensor recordings showing unidentified phenomena. New technology, especially when produced rapidly, can come out with errors in its software or hardware that could be misconstrued as evidence.
• Avi Loeb, an astronomer from Harvard, holds that the investigation of UAPs should be placed into the hands of the scientific community. New, in-depth scientific data and sensing systems can provide the explanations needed, and it's scientists and researchers, not government or military officials, who are best poised to do this research.
• Overall, it remains unclear whether any UFOs we've seen so far are extraterrestrial in origin, but we cannot rule out the possibility. Some can be explained in a terrestrial way, but that doesn't mean others aren't potentially extraterrestrial in origin.

We will never be able to identify everything in the universe, so there will always be unidentifiable objects.

• In 2020 there was 7’000 sightings of foreign objects. This is increasing every year as our scientific equipment including radar imagery gets better.
• As we become more aware of UFOs we register more of them. They are unidentified objects, meaning that we don't need to know what they are, just that they exist. I'm not trying to promote extra terrestrial activity here, that green aliens are going to pop down to earth and say hi, just that there are things out there that we are unaware of.
• The universe is expanding, 7.3 kilometres a second to be exact, and is already huge. There is much of the universe that we will have not seen, and perhaps never will, so there will always be things that we cannot recognise.

If they're not real, you're seeing things.

UFOs, Unidentified Flying Objects, can include balloons, flies, aircraft, shooting stars, asteroids, baseballs etc. You can still see them, but may not always be able to tell WHAT it is exactly.

Unidentified flying objects definitely exist, if we take the statement at the most simple level.

The first type of unidentified object that exists, could be said to be on the personal level.

If i look up in the sky and see an object flying that I cannot cateogorise, then that to me, is an Unidentified Flying Object. If it is not in the category, of plane, bird, balloon, etc. that is where i will put it. This says little about how mysterious the object is and says more about my lack of knowledge, understanding and lack of resources to find out.

The seond type, of object, is one where i may not know what it is, but someone else might know what it is because they are in a position to know, or are willing to put in the effort to find out: like someone in a countries air force, or at an airport, or with binoculars, or with a app that knows what planes are flying presently etc to look for, and identify the object.

I would include in this category, when strange sightings are observed in the sky and a government or some named body go out to investigage it. Of all the named bodies investigating UF'OS, I am not aware of a single body that claims they can identify 100% all the sightings. This could be due sometimes to a lack of accurate information regarding the sighting, or even that the sighting represents something presently unknown to science.

However, there is something to be said about the last category of UFO.

The term UFO, is a loaded term. In that culturally, the term implies flying discs/alien craft, or alien technology. I have seen no convincing evidence that these exist.
Using 'Occam's razor', which states the simplest answer, with fewest assumptions, is the most likely to be the true one, i think the more likely explanation is that there is phenomena in our skies belonging to earth, that we do not yet understand

. Rather than exotic tech from alien worlds, in our atmosphere.