Yes, I agree with everything you wrote, but the caveats are where I’d focus any investigation:
Is the equipment functioning properly?
Are there other plausible interpretations of the data gathered by that equipment?
Some of the best UFO sightings seem pretty similar to ‘ball lightning’ which also isn’t either well-explained or particularly well observed. (I think there’s one plausibly somewhat-detailed observation of it to-date.)
I don’t know enough ufology to know what the deal is there.
I also don’t know enough about specific events, the observations made, the raw data collected for those events, etc..
I don’t know enough about ‘generic UFO sightings’ to answer.
“actually aliens” seems very very unlikely – definitely not literally impossible tho.
My priors are that a lot of historical UFO sightings really were experimental aircraft. I’d expect some number were early drones too. Others seem to have definitely been, e.g. weather balloons.
Other sightings, particularly the relatively well-documented recent ones, seem very similar to ‘ball lightning’, which is also so little understood that it’s not even clear that it’s real. Assuming those observations are both accurate (e.g. the relevant ‘equipment’ was working correctly) and being interpreted accurately, they don’t seem to be drones, unless the drones themselves include novel propulsion systems (which is very plausible assuming the existence of such novel systems).
(And, as a a kind of reference point, ‘rogue waves’ seem to have been similarly so hard to study, until very recently, that their existence wasn’t entirely clear.)