Didn't see it myself, I'm over in Manchester so a bit far from Phoenix lol. But genuinely curious - was it completely silent or did it make any noise? That's usually the thing that separates the interesting reports from misidentified aircraft for me.
I've been following triangle sightings for about 30 years and the silent ones are the ones that stick out. Had a mate in Sheffield who saw something nearly identical back in 2019, same rough shape, same low altitude, gone in seconds. Never got a satisfying explanation for that one.
Anyone got footage or even a rough sketch? Witness accounts are useful but visuals always help nail down the size and proportions. Thats the bit most people forget to note at the time.