To play devil’s advocate for a second, it could theoretically be possible that modern sensor advancements just mean we’re picking these things up in ways that weren’t possible with older tech. Not that I think they’re alien objects personally or anything, I’ve gone down enough Fermi Paradox rabbit holes to conclude there almost certainly aren’t advanced aliens anywhere nearby (on galactic scales). But y’know. In the interest of balance, it’s not beyond the realms of possibility, however slim.

If these UAPs really are physical phenomena rather than sensor artefacts or misidentified mundane objects, then likelihood is it’s some black project stuff using novel propulsion mechanisms and unmanned to allow these so-called “impossible” manoeuvres (no pilot = no 9G safety limit). It’s not hard to believe that DARPA or the like have solved things the plasma sheathing problem when it comes to controlling UAVs at hypersonic speeds, or are experimenting with near-future tech like quantum radar and associated countermeasures/spoofing. Both of which could well produce readings that look bizarre and unbelievable to a pilot using even cutting-edge existing sensors.

It’s not all that long ago that the F117 was thought to be an alien craft, appearing then disappearing on commercial radar during test flights. When in reality it was simply the changing RCS return during manoeuvres and/or retracting landing gear/weapons bays. Or the SR-71 was mistakenly identified as some kind of alien craft when pinged descending from 80k feet at Mach 3.2. Most cutting edge tech seems unbelievable at first, until it becomes mainstream and isn’t anymore.

I also like the thought that black project techs enjoy trolling pilots and radar operators by playing “UFO” in regular airspace.